How can I assign "z" key for enabling zoom tool and zoom pressing with my stylus?.

I try to assign the "z" key and i can't.

I would like to have a soft zoom like I have in Photoshop: y press the "z" key and after that, I press the nib of my astylus and "draw" and I can zoom in and out continuously.

It's uncomfortable for me being forced to press the preselected far keys of "[" and "]" . I use to have all my basic keys near rached with my left hand/fingers and I can't paint under these conditions.

I really love this program but if the configuration of the shorkeys doesn't allow me freedom enough for that basic configuration of my keyshorts...Humm...i will have to comeback to MangaStudio. ...

And I would love to use this when I buy my next tablet surface Pro 4 with the M3 processor...ARGHHH.

Cand you change the assignation of the "z" key to the zoom tool of this fantastic program?.

Thanks in advance.