Yeah, the manuals are written in 'Jinglish' , there are a few options, but if you have macro A & B, this allows parametric programming and you could use G65 followed by the values you want to plug into the specified variables in the subroutine that is called by the G65. You would then have to write the subroutine only once.
If you want to do any Macro programming in length, I would recommend getting hold of a 3rd party book on the subject as there is a quite a bit you can do in the way of programming. I believe the canned routines such as G74 exsist in the programs 9000 & up. Hopefull someone here may have done this particular routine to help you get started.