locate Outlook local file w/Server??

This is a setup question

Setup:
*Windows Server 2003 standard
*Using hosted exchange server (MailStreet.com)
*Local pst files are set up on the server for each user.
*Desktop PCs have Outlook using the server pst file as the default file.

Benefits:
*Avoid limit at MailStreet for accounts
*everyone’s pst file is backed up
*Have access to new and old email via in-office desktop and by connecting through TS and running it on the server.

PROBLEM:
They have their first laptop as a desktop replacement. He cannot access Outlook unless connected to the server since the default pst file is on the server.
MS does not let me set the pst file as an offline file.

Any work around?
I know the obvious solution – move his pst file to the laptop and setup a backup routine for him. Just looking to see if I missed something

Thanks in advance…