Was a “Classified” doc. printed/copied?

We have a series of very sensitive corporate documents that about 10 users have access too. The users are not to copy nor print the files but as we all know a disgruntled employee could do just about anything.
Is there a way to track (Audit) a file to see if it has been copied or printed?
Currently we are running NTS4.0 but these files could be moved to a W2K Server if there is added functionality there.
Thanks,
Rob