You can use the Remote Desktop feature in Windows XP Professional to connect to your computer from another, remote computer. WARNING: The Remote Assistance feature in Windows XP may not work properly if you change the listening port. To change the port that Remote Desktop listens on:
Start Registry Editor (Regedt32.exe).
Locate the following key in the registry:
On the Edit menu, click Modify, click Decimal, type the new port number, and then click OK.
Quit Registry Editor.
NOTE: When you try to connect to this computer by using the Remote Desktop connection, you must type the new port.
Update: I forgot to inform you that you need to add this to the default.rdp file for the XP terminal client... Add this line anywhere in the file.
server port:i:your port number
ie server port:i:21