Scripting Entourage for .Mac Aliases

Does anyone know if it is possible to create an AppleScript that would put in a return E-mail address that would relate to a .Mac alias. I have four .Mac Aliases and can easily choose these from However, this is one of the reasons I migrated away from Entourage. I was thinking that maybe its possible or maybe its already been done, so that when you create an E-mail or reply to an E-mail you can choose one of your aliases as your return/send E-mail address as opposed to the default in the E-mail account. Before I attempt this, I’d really like to know if something like this is possible.