Rod - I believe you can set up an event at the system level to do this. You'd want to add an event at Settings>Events from a system administrator account, configure the event as a Message Received or Message Sent, configure the TO/FROM address as the alias name, then configure the action to add recipient as you've done before. That should do the trick! We can submit a feature request to add functionality in the future that will make this process simpler though!