Is this possible, if so how?

I have an xserve running jaguar server with 5 ip addresses configured on the built-in ethernet card. Is it possible to forward one of those ip addresses to another machine connected to the pci ethernet card. In another words: 68.15.??.?? -> 10.0.0.1 Public ip request -> private ip server The reason, I am posting this question: I want to run an old version of webstar/lasso on mac os 9 on an iRack, without purchasing another connection from our colocator. Thanks, Dustin Hood