Alternate EXE call???

I was nosing around my USB drive when I noticed that the Firefox portable INI file made this statement:

"The FirefoxExecutable entry allows you to set the Firefox Portable Launcher to use an alternate EXE call to launch firefox. This is helpful if you are using a machine that is set to deny firefox.exe from running. You'll need to rename the firefox.exe file and then enter the name you gave it on the firefoxexecutable= line of the INI."

I am currently stuck using computers in the public library, which will not permit the running of EXE files. So my question is: how do I set up an alternate EXE call? In what way do I need to change the program name? I did a search both on this site and via Google but no dice. All help is appreciated. Thanks people.