You Need a USB to RS-232 (male serial) adapter. I have a Keyspan for my DSMlink but there are a lot out there from $15-$40 (office max has one for $40) i bet radio shack would have one, maybe even walmart??
http://www.tigerdirect.com/applicati...gtCjCVRqCjCVRq
http://www.tigerdirect.com/applicati....asp?CatId=464