..it is already in use on a server

If you have a CGI script normally you need a server in order to see the output in a browser. You can also run it from command line producing the html output: see Testing out a CGI script using the command line for more on this subject.

Running CGIs on a windows web server (aka IIS) is normally a font of big headaches, and may lead to different use in respect of the original server. The best will be recreate the same environment of the original server using a virtual machine.

Consider also that CGI is an almost dead tecnology and if you are not a programmer maybe not worth to learn it.

HtH
L*