Remote desktop web connection

I read that you can use a Windows XP computer as host for a RDWC session on
another computer running Terminal Services. Does this computer have to be on
a network with the host computer, or can they just both be connected to the
internet?
I have a Windows 2000 Professional computer running on an office network
behind a firewall, and a home computer running XP professional (static IP,
broadband), with RDWC configured. If I am at an internet cafe, can I log
onto my Win2000 office computer using the home computer as host? (I can have
the home computer connected to the office network via VPN if reqd)