Fans, critics, and performers would probably agree daytime doesn't need another rape story line. But even skeptics have been won over by the gritty performance of Guiding Light's Sonia Satra, whose character, Lucy, a victim of a date rape in April, is now coping with the aftershocks of the crime. Satra whose role recently consisted mostly of uttering lines like ''Alan-Michael, you have a message'' to her boss admits she was ''concerned'' about the depressing plot, and researched her part by reading books and talking to rape victims. A New Jersey-born ex-commercial model, Satra, 23, is enjoying her new prominence, which will likely grow once Lucy starts a romance with Alan-Michael (Rick Hearst). ''A lot of fans come up to me, saying, 'Oh my God, you've gotten so much better,' '' she laughs. ''I'm not sure how to take that. I guess it's a compliment.''