remember that you wont be able to use the same CD key on both of those computers and play at the same time....
but yeah you need to open all of the 27000-27999 ports. THat catches almost ANY game out there, except for the servers that dont want to been seen most of the time...but I thought winproxy 2 let you use NAT? if it does, use that. If you have 98se, me, 2k just use the internet connection sharing from that...its pretty easy and you dont have to worry about the software configuration that much...
Also, I think it was either winproxy or winroute that would shut my connection down if I tried to update my server list...(probably the amount of pings coming back when you ping all the servers)...good luck!!!