You can tell Virtual P(iece of) C(rap) version 5 in Settings (for a Virtual machine) -> Network -> Virtual Switch to give your VPC a separate IP address. That means that you either need to have a DHCP server on your network, and your virtual PC configured to use DHCP, or you need to find a valid address on your network and manually set the VPC to use it. Your cable modem might not let more than one computer use it at a time. Some of them only give at one DHCP address, and link that to the computers hardware address, and will not let packets from a different hardware address to go through the cable modem. If you have jaguar, you might be able to use the built in internet connection sharing to share your cable modem connection (but I doubt it).
One important thing, you can't use the remote desktop without having the terminal services running on the PC. That means Win XP (and I am not sure if the home edition has any limitations on the remote desktop use). Under 2000, I believe that you need to install this service separately (and have a license to install it).
Hope this helps. BTW I wouldn't install XP under VPC. It is slow as **** when your constipated.