appinfo.ini start field ... how to create the .exe

Hi all,
Creating my first portable app .. im stuck on the bit in the app documentation that says ...

"Start is the command line to execute to start the app relative to the AppNamePortable directory. This will typically be AppNamePortable.exe."

How do I make the .exe file?? and how does it point to the actual executable in the App\Appname\ directory?
I have a .bat file that works perfectly, I just cant figure out how to create the .exe file ...

Thanks