I didn't check, but I find it hard to believe that Radio Shack would not have what you are looking for. Radio Shack always seems to have whatever sort of adapter, connecter, whatever that I might need. I'm rather surprised that your GeFroce didn't have the converter dongle included. My ThinkPad came with one. If all else fails, call up IBM and see if they'll sell you one.
Zenmervolt
EDIT: Those prices on the site that was linked to are astounding. Why would anyone pay that much for an adaptor?