Using a Windows' box internet connection from Linux

Hi, This might be a Windows issue, but I am sure somebody else is in the same situation. We have a Windows server at work that has a permanent connection to the internet. I have a Linux laptop that can 'ping' the servers IP address and do other things (FTP etc.), but I can't work out how to use its internet connection. I know the internet connections IP address, but can't ping it or anything. Any ideas would be appreciated. Cheers Phil