TV comedy scribe and performer Jennifer Saunders (“Absolutely Fabulous”) will pen “Viva Forever,” the previously announced stage tuner from “Mamma Mia” creator-producer Judy Craymer based on the music of the Spice Girls.“Viva Forever” uses the song catalog and “girl power” ethos of the ’90s U.K. pop group. According to press reports, the show will have fictional characters and will be neither a bio-musical nor a tribute show. Gig reps Saunders’ first time as the writer of a tuner. “It has a glimpse of the underbelly of TV talent shows, an invented show and a little bit of comedy romance,” Craymer promised. Creatives and cast have yet to be set.