Recab, thanks for posting, there are a lot of good, fundamental questions in there that we can help you clear up.
A static IP on your Windows 2003 box will appear when you get on that Windows 2003 box and run the command 'ipconfig' in the command line. It is your IP on your LAN (your LAN comprises all the boxes that are located logically 'behind' your DSL router). When you go online to check your IP, what is being returned is the IP of the DSL router - the IP that your ISP has assigned to you (not the static IP of the Win2k3 box). This is why most small networks are able to be set up as 192.168.x.x IP ranges, because those aren't able to be directly seen on the internet (so they can be duplicated, just not on the same LAN).
A gateway is the device that allows communication from the current LAN out to anther network (in this case the internet), so your gateway is your DSL router. There are a few different setups that are possible here, but what would happen would be more devices sitting immediately behind your DSL router to perform various other tasks - a box to create a DMZ so that you can have a web server, a box to act as a firewall, even another router or switch to allow a larger network behind your DSL connection.
From here, we need to clarify your issue a bit more - can you go into the Win2k3 box, open a command line, and type 'ipconfig' and tell me if that is the proper static IP? If it is, what are you attempting to do with that static IP? Get a connection in from the internet? Connect another computer to it?