MS Exchange Forwarding

I have a newly setup microsoft exchange 2000 box. I need to forward mail from user@ourdomain.com to sameuser@anotherdomain.com
What is the process for this?
I have created a user@ourdomain.com however when i try to forward it wants me to pick a contact. Do I have to create a user and a contact? Or can I just change the email address for the user?