Film legend Sir Richard Attenborough says he had a great time playing Santa Claus in the current remake of Miracle on 34th Street — save for one incident. ''As I was riding on that marvelous sled down Central Park West with a huge parade of bands, I felt fully in control of everything,'' says Attenborough. ''Then I looked up and saw a man sticking his tongue out at me! It was Michael Douglas, the rotten sod.'' Douglas, who was watching the filming along with other bystanders, once starred in Attenborough's A Chorus Line in 1985. Douglas didn't stay naughty very long, however. Says Attenborough, ''He did ask me to lunch after.''