Automatic Forwarding Exchange 5.5

I want to track an e-mail that comes into my system from a Yahoo/Hotmail accout. This person from Yahoo/Hotmail acct send e-mail to few of my users in my domain. What I want to do is to have every mail that comes from this person come into my mailbox and also 1 copy goes to the destined user automatically.
Is this Possible ? and how ?
I am using Exchange 5.5 on NT 4.0.
Any help would be appreciated !!!