I don't know why it doesn't work. As I mentioned before, it could be due to your motion controller. Macros can behave differently with different motion controllers.
Mach3 is at the end of it's life. Development stopped over 5 years ago. Documentation was always sparse, so your not going to see any new documentation now.
There is a Cypress manual, and a Mach3 programming manual available to download.
THe Wiki contains 99% of the Button, OEM and DRO numbers. There is a post somewhere here on the forum that may have a few more obscure ones in it, if you search. But the Wiki should have everything you need.
As for the Vars, as I said, they are not documented, except for a few in the manual. I've never seen a list anywhere, and I suspect that only the developers have a full list.