Gentoo and Windows ICS

[Kirja]

I have just installed Gentoo on my pc upstairs which is networked to my families pc downstairs which runs winxp and is my internet gateway (I know its not ideal but thats just how it is).

During the install of Gentoo using the livecd, the internet connection sharing (ICS) enabled on the xp machine was automatically detected and configured and everything was fine.

Being new to Linux I now need to know how I can configure my newly installed system to make use of the ICS and allow my gentoo box access to the net. My onboard ethernet (nForce2) is properly installed and shows up in /sbin/ifconfig.

If you could help me configure my system I would be most grateful.