Can AddOns select a spell without casting?

[xexrez]

Or anything in the action bar for that matter.

I get that the actual casting of a spell must be a hardware event, but is there a way to scroll through the spells/items in your action bar via key bindings or mouse wheel or whatever you'd want to use, and then bind a key to "use" ?

I didn't know if this fell under "targeting or untargeting any unit." And if it does, my bad.

I saw an add-on called Quartz Modular bar that says *Target/Focus Implementation of target and focus casting bars. I didn't know if that would be what I am looking for?