B'WAY PLAYS THE NAME GAME By LARRY WORTH ------------------------------------------------------------------------ BROADWAY'S most common backstage story is the old "42nd Street" saga in which the sweet young thing replaces a veteran actress at the last minute and becomes a star. As for the second most popular ... Once the initial hoopla dies down, a once-hot play or musical needs new blood to keep ticket sales healthy. And there's nothing like a "name" to bring flocks of fans to the theater. The latest troupers to put their spin on well-established roles include Lucy Lawless, a.k.a. "Xena: Warrior Princess," opening tonight as Rizzo in "Grease"; pop tunester Deborah Gibson, currently in rehearsal as Belle in "Beauty and the Beast"; and Kimberly Williams, renowned from the two Steve Martin "Father of the Bride" films as well as TV's "Relativity," as confused heroine Sunny Freitag in "The Last Night of Ballyhoo." While the three twentysomething actresses bear similarities in their reasons for coming to the Great White Way - basically, to stretch their proverbial wings - each has a unique tale about her method of arrival. The role of Rizzo, the "bad girl" in "Grease," has been filled by one celeb after another since the revival opened at the Eugene O'Neill Theater in May 1994. Starting with Rosie O'Donnell, Rizzo's Pink Ladies jacket has passed to the likes of Maureen McCormack, Brooke Shields, Joely Fisher, Jasmine Guy, Sheena Easton, Jodie Watley, Tracy Nelson, Mackenzie Phillips and Debby Boone. But none of the various Rizzo auditions could match that of Lucy Lawless. On hiatus from her New Zealand-based "Xena" schedule, Lawless was a guest on O'Donnell's talk show when she spontaneously broke into a chorus of "I'm an Old Cowhand." "Grease" producers were not only watching, but immediately roped in. "They made me an offer and I jumped at it," says Lawless, who's admittedly nervous about tonight's official opening. "I loved the thought of singing for the hell of it." Actually, the 29-year-old Auckland native has sung exclusively in the shower for about 10 years. Before that, she starred in one high school musical after another. The bad news: She had picked up a lot of bad vocal habits. "That's why the producers have been tutoring me," she says. "They've been completely amazing and totally supportive." Ditto for Angela Pupello, who's played Rizzo since April 8. But watching Pupello's expertise as a dancer proved intimidating. In fact, the required fancy footwork has been Lawless' biggest concern. "My Rizzo will have to be a different take on the character," she says. "They've retooled things slightly, letting me focus on my own energies and what I can bring to the part." But that doesn't mean Rizzo will be making eyes at good girl Sandy. Unlike her "Xena" character, there'll be no Sapphic themes. That's a relief to Lawless, who says people constantly comment on that aspect of the show. In reality, Lawless has a 9-year-old daughter, Daisy, and is "partnered" with Rob Tapert, who produces "Xena" and "Hercules: The Legendary Journeys." Both will stay with her during her seven-week run as Rizzo. Then it's back to New Zealand for more 14-hour days, five days a week, as Xena, a role to which she's committed through the year 2000. If Lawless needs any tips on refining Rizzo, Deborah Gibson could ably assist. Gibson not only played Rizzo in the national touring company of "Grease," she made an indelible impression as virginal Sandy for nine months in the musical's London incarnation. Though best known as a singer, Gibson now has acting experience on her resume. Besides starring in two indie films, she made her Broadway debut in 1992 as Eponine in "Les Miserables" (four years after its opening) and played Fanny Brice in a revival of "Funny Girl" that closed before reaching Broadway last year. As a pop superstar by age 15, the 27-year-old knows about show biz's ups and downs. Her current high comes from the prospect of playing Belle in "Beauty and the Beast" at the Palace Theater. "Belle is actually a gutsy move for me," Gibson says. "Doing edgier things, like working with Junior Vasquez or Circle Jerks, got a positive response. For this, I'll probably be criticized for reverting to cutesy. "The difference is that I don't care. I'm comfortable with who I am. I think I'll always be best at traditional family entertainment. To me, this is a match made in heaven." Gibson will be the fifth actress to play the charming Belle, originated by Susan Egan in April 1994 and currently played by Kerry Butler. Gibson takes over on Sept. 24. The opportunity arose six months ago, shortly after "Funny Girl" had run its course. Gibson had retreated to her parents' home in Merrick, L.I., having just fine-tuned her latest album, "Deborah." The nine-month contract seemed attractive, allowing a respite from jetting between countries for concerts and appearances. "The idea of settling in, being able to make weekly appointments with my voice teacher, see my parents on a regular basis - whatever - was perfect. The thought of a sane and normal existence really appealed." At least until checking out Belle's high kicks in the "Be Our Guest" number. "I'm all enthusiasm and no technique when it comes to dancing and movement," she says. "But I'll get there. And to those who think I can't, I dare them to come see me. I always remember my first "Les Miz' review: "I came to pan her, but I couldn't.' "Believe me, I plan on doing a great job in anything I take on." As for recently changing her professional name from "Debbie" to "Deborah," Gibson notes that her family and friends have always called her Deborah. "Besides," she adds with a grin, "it's not as drastic as "The Artist Formerly Known as Debbie.'" The name game isn't a big deal to Kimberly Williams, but she wants to be known for her own accomplishments rather than as girlfriend to tennis ace Pete Sampras. She's made a definitive step in that direction via her Broadway debut in this year's Tony Award-winning best play, "The Last Night of Ballyhoo," at the Helen Hayes Theater. Williams began her six-week engagement on Aug. 26 in the role of Sunny, a part loosely based on the mother of "Ballyhoo" author Alfred Uhry. The casting seemed serendipitous. Williams was simply passing through New York (her parents live in Westchester) when she heard that Sunny's role was being recast. The part's original cast member, Arija Bareikis, needed to take a leave of absence to fulfill a film commitment. "I saw the play and loved it, then auditioned, got the part, and that seemed to be that," Williams says. "At least, till rehearsal." Going into a group that's been working together for six months proved daunting, especially for someone with no stage experience. "I got two weeks of rehearsal, with the director popping in and out," she says. "You do a lot of work on your own. It was pretty scary, and pretty exciting." Long talks with Uhry helped, as did audiences' overwhelming applause (led one night last week by Sampras, who was in town to play in the U.S. Open). "Being on Broadway has been a dream for as long as I can remember," she says. "And I'm loving everything but those two-second costume changes. It's a sure way to lose inhibitions." On second thought, those were lost when the 26-year-old actress feigned heavy-breathing sex scenes on last season's now-defunct "Relativity." The sequences had her mother "climbing the walls." But they also provided distance from her ingenue role as Martin's daughter in "Father of the Bride" and "Father of the Bride Part II." "A lot of people still think I can only play a goody-goody," Williams says. "That's why playing Sunny - a woman who knows how to push others' buttons - has been so satisfying. "And if my name brings some new attention to a wonderful show like this, it's a great deal for everybody."