Should be easy but likely to take you some time.
You sound like oyu want to be using Internet Connection Sharing (ICS) included with windows from (?) 98 up.
Basically configure the computer with the internet connection to share it, and set the network tcp/ip ip address to 198.162.0.1
then configure the second (third, fourth, etc) computers network adapters tcp/ip protocol to be automatically assigned an ip address. get to internet explorer, tools, internet options, connection, lan settings, clear all boxes.
GO... ...maybe.
Should be able to find more on google. If both computers are using windows xp then you can use the network connection wizard to do it really easily. if it works for you.
Good luck