The Pro/Program is located IN your part or assembly. So if you open that part on a different computer, you'll still have all the code.
I strongly recommend using a PDM system, which can assure that you have unique filenames, so you don't end up with identical filenames in different folders.
As for Pro/Program, it's a super simple BASIC-like language. If you know IF...THEN..ELSE then you can programm with Pro/Program. Suppressing features is super easy, just enclose a feature (at part level) or a component (at assembly level) with an IF STATEMENT and you are good to go.
I would also recommend using Notepad++ as your editor. You can even define a language for Pro/Program, so your code will be a lot more easy to read/edit. Take a look at this post here.
I'm using Pro/Program a lot but main disadvantage is we lost Undo / Redo functionality
I hope PTC soon will fix it...