CANNES — “I don’t want to sell things,” Robin Williams told a packed press conference Thursday at the Majestic Hotel. The actor was confirming that he’d rejected an offer to do McDonald’s commercials, but seemed to ignore the irony that he was there to sell the upcoming film “What Dreams May Come.”The press meet was dominated by Williams’ constant comedy riffs — and by so many questions unrelated to the film that moderator Don Ranvaud kept reprimanding the media: “I think it would be good if we sort of focused on the movie a bit.” Cuba Gooding Jr., for example, said he has committed to “In Too Deep,” saying, “It’s a Miramax thing we’re developing,” but declined more details. Williams said he doubts there will be a sequel to “Mrs. Doubtfire,” but he expects to do the long-delayed biopic of Father Damien of Molokai within the next 18 months to two years. The press did ask some questions about “Dreams.” Gooding said the pic’s budget will be $70 million, and Polygram Filmed Entertainment Intl. prexy Stuart Till said it begins shooting June 23. The production, from Interscope Communications in association with Metafilmics, will be distribbed worldwide by Polygram, which is targeting a fall 1998 release in the U.S. The film concerns Williams’ journey through heaven and hell to be reunited with his wife (played by Annabella Sciorra). Director Vincent Ward described it as a “very moving and emotional story” and “an intimate epic.” He said he’d turned down Ron Bass’ script (based on Richard Matheson’s book) because he couldn’t figure out how to film it; however, a month later, he came up with an idea, consulted with Bass and they went to Interscope. He said they’re on the fourth draft now. Asked about the afterlife and reincarnation, Sciorra mused, “I’d like to come back as a transvestite,” explaining it’s “the most exciting thing to come back as.” The majority of questions were addressed to Williams. And when they weren’t, he piped in during others’ answers, such as pretending to translate Till’s comments into French, German and sign language. Williams also imitated the accents of the reporters, described Cannes as “Disneyland by Dante,” imitated the Spice Girls and joked about subjects unrelated to anything else (“They’ve had cloning in the Deep South for years. It’s called cousins.”). The actor had a few serious moments, speaking of his fears of technology that can revive dead actors for TV commercials, and wondering aloud about reports that his friend Christopher Reeve is regaining sensation and is off a respirator. “I want to get him off that as quickly as possible,” he said, but even these sober moments were interrupted by manic jokes about crying babies and ringing cell phones in the room.