aliasing one domain to another?

I'm looking at upgrading an ejabberd server that was setup by a former employee at the company I work. He setup the server with the jabber domain @jabber.company.com which has been confusing people for the last several years since most people expect and automatically type in @company.com like is used for our email addresses.

I'd like to migrate the server so we use @company.com but with several hundred users simply shutting off the old server and starting up a new one with a different domain would create a nightmare rush of work reconfiguring all the clients.

So I'm trying to find an option to allow for a smoother transition, another tech I know claims to have in the past setup an ejabberd server so that two vhosts on the same server were aliased together so that user@jabber.company.com was treated the same as user@company.com (signing into one domain as that user makes the user show as online on both domains and messages sent to either id end up at the currently signed in used). However despite digging through the manual and looking at all host and vhost options I can find I'm unable to find a way to make a second domain be treated as an alias to the first.

Can anybody help me here, is it really possible or is my coworker confused? (and if it is doable any pointers at the config required to make it work would be awesome).

Thanks
-J