When Al Madrigal walked in to audition for the comedy “The Ortegas” he realized he was a longshot.But look who’s laughing now. Madrigal stars in “The Ortegas,” Fox’s adaptation of the International Emmy-winning BBC comedy “The Kumars at No. 42.” The skein is a mix of family sitcom, talkshow and improvisational humor. Madrigal plays Luis Ortega, the son of Mexican immigrants who indulge his dreams of becoming a yakker host by building a television studio in the back yard of their humble Van Nuys, Calif., home. A year ago the San Francisco standup comic was honing his craft in Bay Area comedy clubs and taking the stage with his improv sketch group. Things started to take off for the 31-year-old at last year’s annual New Faces showcase at the Just for Laughs Festival in Montreal. “What I think got me the show was my sketch comedy background,” he says. The improv comedian seems a perfect fit for the multifaceted nature of “The Ortegas.” The show requires Madrigal to perform unscripted interviews with real celebrity guests, acting in a traditional sitcom role, as well as improvising scenes with co-stars Cheech Marin, Terry Hoyos and Renee Victor.