VPN wont connect

[Guest_imported]

I've setup a VPN on W2K server, when I'm in the office and "tunnel" my way through the net using my office IP I can connect to the server, however when i'm at home and dial into a ISP and get a different IP and then try to get to the VPN server it comes up with a message saying i need to get the proper encryption authentication...(for which i need to have a certificate from the server...fine...

i installed certificate services(CA) on the server and created a new ccertificate and then issued it to the client machine, but STILL when i try to get to VPN i get the same message, and also i cant ping the server i'm trying to connect to...do i have to re-direct that server to a proxy or something so its visible on the

http://www...if

so how can i do it?....
Pls..any help would be greatly appreciated!!

 

[snyper111]

Add-on for the above question-
Network setup:
-- RAS,Proxy server is a NT4.0 connected to a Cisco 1600 series connected to the ISP, with no PPTP or L2TP ports configured on the router
-- The VPN server is on a W2K system(w/ DNS,WINS) on the same network but on a different domain