Nsis script

I don't know about a PHP script, but a template to do what you suggested has already been made.
See this POST
Also NSIS Portable is available from this site.
Making a portable app "a launcher really" is as easy as putting in the information you mentioned, and dragging the script to the portable nsis window.
Obviously this won't work for all apps, but it works well.
I've created launchers for several apps with it.

It was written in AutoIt, has the option to create just the script or to compile it and create the *.exe. Here's the link:

https://portableapps.com/node/5164

just download pafappmaker.exe, it's the 2nd link on the list

for Libertà Lapwing!
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Ryan McCue
Person 1: Oh my god. You will never believe what just happened.
Person 2: What?
Person 1: I can't remember, I've forgotten.