Reply on redirected mail in Microsoft Exchange 5.5

[karkarkitkat]

With Microsoft Exchange 5.5, I am using a custom recipient to redirect mail that is sent to a mailbox on our server (we'll call it user@work.com.) This mail is then redirected to a user's aol account. This seems to work OK. However, when the user reads the mail from aol, he wants to reply not with the aol return address but with work.com as the return address. Can't seem to find how to do this. Any suggestions would be appreciated.