Win NT Login

i login to WIn NT 4.0 Domain from my Win Xp machine. on my local machine (i.e Win XP ) i have administrator rights. but on Win NT PDC i have only User rights. when i login to win NT Domain , I loose Admin rights on my Local Computer ( Win XP) .To do admin tasks on my Local machine i have to logout from win NT Domain & login to Local Computer. how do i get my Admin rights on local machine having logged into Win NT domain .