Exchange 5.5, Replacing missing free/busy mail box

[chifu]

I migrated my user mailboxes from an old Exchange server to a new one. Then wiped the old exchange server.

Afterwards found that there were hidden system mail boxes which needed to be taken across as well. I need to replace the hidden free/busy mail box, has any one managed this, when the Exchange server that the mail box was on no longer exsists. Need to know how to firstly create a new free/busy mail box on the new server and then change all user mail boxes to point to the new free/busy mail box.

Thanks for any help that any one can give.