VPN:NT2000–>NT4.0 w/Proxy 2.0

How do you implement a VPN connection via the Internet between a Windows 2000 server and a Windows NT 4.0 Server with Proxy 2.0 installed on both servers. Both are seperate NT domains and seperate locations

-Win 98 Clients at NTSrv 2000 locationneed to access IBM AS400 and Novel files at the NTsvr4.0 site
-Win 98 clients at NTsrv 2000 site logon to NT 2000 domain
-Win 98 clients at NTsrv 4.0 site log onto Novel but use NTsrv 4.0 domain for Exchange
-Both sites are on seperate private IPschemes
-Both sites have internet access
-Both Servers have 2 NICs (proxy)