That default AHK script you were using doesn't pass the movement keys at all, just 1-10 and - (as well as alt, ctrl and shift of those numbers)

to use it properly you set a

/assist player1

macro to your "=" key and a

/follow player1

macro to your "-" key

Elsewhere in the wiki you'll see that it suggests passing the movement keys only to your followers, so you can move them as a group independant of your leader (this is really important for avoiding the followers not casting because something isn't in front of them)