ah sorry gerard i am used to server 2008r2 was testing with a small business server 2003r2 but that doesnt support group policy preference which does make things allot easier for yourself. You would probably have to run a logon script similar to mount a network share but i cant think offhand how to write one for what you need.
I have one for mount a share to a user its like this
net use F: \\servername\sharename\
now agian this was just testing at the time with SBS server 2003r2