I think I understand what you are trying to do, but you may be taking a more difficult approach. Am I correct that you want both versions to be used via a web browser?

Because of the interactions of the browser and the server via forms and CGI, you aren't going to be able to do it simply without different versions of your script and specific configurations made on the client browser. Of course, with perl, there's always more than one way to do it.

Probably the solution requiring the least modification to your code would be to put everything needed on the CD.

The CD needs to have a web server, perl, and all your scripts. If you are on Win32, have a batch file that starts the server on the CD and then get a web browser to go there. It'll be tricky no matter what, but good luck!