Button Positions

So for my map I need to have certain button positions.

I want it so I can press Z, and it will press the spell that is in the Z part of the grid.

It doesn't work, though I don't understand how I make them go (on the bottom line) like:

0 1 2 3

Any help?

It's not like a normal grid.

Which way is X and which way is Y? I forget.

Also where would I change all this in the Object Editor?

(X, Y): X is horizontal, Y is vertical.

You can find those in "art - Button position" fields in WE.