DIE HARD star Bruce Willis insists the hardest role he's ever played was RJ the raccoon in his latest animated film OVER THE HEDGE. The actor has starred in over 70 movies from The Sixth Sense to Pulp Fiction, but found producing fine acting alone in a sound recording studio tougher than anything he'd done in the past. He explains, "The hard part was all the actors work by themselves. No one even worked together. "It took about a year and a half to get all the lines looped and the story done and recorded . It's just me and the mike (microphone). "It seems like when you watch the film we're all over at somebody's house with microphones and sodas and pretzels going, 'Hey let's just talk about the movie.' "But no one ever worked together. So it was difficult. "It's a comedy and you want to be funny, but there's no timing, there's no way to get a rhythm going or anything like that so I was always saying, 'Is that funny?' Is that what you want?'"