Exchange 5.5 Containers

I have Exchange 5.5 SP4 on an NT4 server. When this was originally set up our company only had one facility so all Mailboxes were set up under the Receipients container. We now have facilities in 4 states and all are residing on the same Exchange server. I am trying to organize the mailboxes so I created different containers for each state under the receipients container. Now for the hard part. In order to put the current mailboxes in their correct container I have to create a new mailbox and copy everything over to it and then change the users Outlook profile to point to the new mailbox. This is going to be a headache. Does anyone have an easier way to do this or a better way to organize the mailboxes?
Thanks in advance.