Out look 2000

I am currently running workgroup mail on an NT 4 server.All of my users run outlook 2000 and have there Pst file located on the network via a shared drive.How can I configure a a users email to forward all of there in box messeges without that forward showing up on there side? I have tried the rules wizard.That leaves a trace on the end user side.Help.This was a request from my superiors.