You could record a macro to get the syntax and modify that recorded macro to do
what you want.
Then you could place a button from the Forms toolbar on the sheet and assign
this macro to the button.
But an alternative would be to add a couple of buttons to your favorite toolbar
(xl2003 and earlier).
In xl2003 menus:
Tools|Customize|Commands tab|View Category
Scroll down in the commands listbox until you see:
Zoom In
and drag it to your favorite toolbar
Do the same with Zoom out
I don't know if the same icons are available in xl2007 so that you can add them
to the QAT.
By putting these icons on your favorite toolbar (or QAT if available), you'll
have this functionality in all worksheets.