Replacing certain parts of a document

Hello.Handy forum.First post here.

I hope it hasn't been answered before (searched a bit):

I have this word file with some programming code.I need to change specific parts of the code every time according to, let's say, the id number of a shop belonging to a bigger chain of shops.

So i would like to insert something like "Shop id: XXX" on top of the list and specify exactly which parts of the programming code i want to replace each time, so when i type id "100" for example, changes are made accordingly.

Thanks in advance.