I am hosting a small site on my IIS5.1 Server on Win XP Pro which is on a network. My ADSL line however is connected to my OSX Mac. I need to know how to connect to my XP machine from outside the network (ie from the internet) and view he website etc. I've been advised that port forwarding is the answer but i'm not very sure what this involves or how to do it. My setup is shown below.

My Mac is connected directly to the Net via a ADSL line. This is then connected to a D-Link DES1005D 5-Port 10/100 Fast Ethernet Switch. All my other computers are also connected to this Switch. My other computers are 1 WinXP Pro machine which uses the Internet thru the Mac (which is set to share internet in System Preferences) which is permanently connected to the network and 1 Mac G4 Powerbook which is connected as and when required. Both the client computers are able to browse the internet and send & recieve emails etc.
Thanks in advance for any info you can supply.

Chris