You would have to use vnc then (since remote desktop requires xp pro), install free edition of VNC from here (i would recommend letting installer install the server as a service) :
http://www.realvnc.com/download.html

You would also download the vnc viewer nokia app (should work on either 770 or 800) :
http://vncviewer.garage.maemo.org/

You would need to go through initial configuration of server, search this forum for help setting up theres a number of threads... here's one :
http://www.internettablettalk.com/fo...ead.php?t=8248

Mainly you will probably need to set windows firewall and/or open up a port on router if you want to remote from outside lan.