single logon to network and in the field

I have a user ABC, domain XYZ who has a customized desktop when connected in

our office. Since this is a portable computer, it is used away from the

office. We connect multiple machines together in the field using a switch,

but the user cannot get his customized desktop since he cannot login to user

ABC, domain XYZ in the field. The only way we can connect in the field is to

use the login ABC and domain being the name of the local machine. Is there

any way in XP to use the same user and domain combination that is used in the

office, out in the field?