If Dustin Hoffman had his way, he'd be writing characters instead of playing them. Hoffman, who is to receive the American Film Institute's Life Achievement Award tonight, said he's not entirely satisfied with acting and has been secretly writing a screenplay for years. "My first choice would be to be the author," he told the Los Angeles Times. "I can't help being this way." Hoffman, whose off-screen interests also include painting and music, has three decades of acting under his belt, yet considers writing one of his dreams. "Maybe someday I'll break through," he said. "You're always looking for something that ultimately you probably know is beyond your reach."