What are the options for a temporary laptop within a work domain?

This is primarily a home laptop, which comes to work once in a while.

Does the laptop have to join the domain absolutely, I thought there were different ways of handling this situation.

From his laptop the user wants to be able to access the files on his desktop pc part of the domain.

Then bring the laptop back home and the laptop not depend on the work domain at all.

The DC is win2008R2 and the laptop Windows 7

Solution 1:

Could the laptop user just connect to his domain desktop via RDP?

He may access file shares on the domain desktop, from the non-domain laptop, provided he uses his domain credentials to connect.

Solution 2:

VPN + RDP is the first solution that comes to mind. As a alternative you could set up his personal laptop to have the option to boot from a VHD file with a work (domain joined) image. This has the benefit of allowing him to sync files between the 2 pcs and work offline.