Thanks, some of that's clear, some I'll have to re read and consult the manual on.
So I could do this:-
in Gcode; M100
In macro M100; Code "M98 P112" (or o, or whatever it is, can't remember at the minute...)
Back in Gcode (o112), do some code
M98 P113
and then o113is basically the line after the line where M100 was called from.
Is that right? Seems sensible if so.
Where do I learn about #Var particularly, and using params? I searched the programmers manual for #var; it doesnt exist there.