Setting up proxy with ssh/cygwin

[Jengu]

I have a gentoo box behind a firewall. I have another box not on my LAN but outside the firewall, running Win98. What I want to do is setup the Win98 box as an ssh server using cygwin (or maybe sshwindows). Then, say I want to use a port on my gentoo box that is blocked by the firewall. I want to use ssh to request that the Windows machine (which is not behind the firewall) to get what I want, and then send it to me over ssh. I think this is called port forwarding.

I can setup the windows box to run ssh and ssh into it fine, but I'm not sure how to have the windows box do the port forwarding, or setup my gentoo box to know which ports it should just try to get normally and which it should try to get over the windows box. I want to try to make this as automated as possible.

Can someone inform or point me towards a good tut/howto?