I'm not absolutely shure about windows doing port forwarding, because i did investigated for another application and didn't found a native solution. But i had success with Cygwin and the ssh.
Basicly wath i did was to use ssh over the windows box with the Cygwin version, then ssh has the
Windows can do it..
I had a broadband failure a while back.. and the only spare modem I had
was on a windows laptop.
I setup the backup dialup connection on the laptop, and set it to port
forward the required ports to the internal machines and connected.
It worked fine. so I know that windows