Diablo-style attacks

Hey all, I'm kind of working on a sort of RPG campaign, and I was wondering if anyone knew any sort of triggers that would let you do a Diablo-Style attack, meaning, if I right-click on an opponent, the player character will attack him just once, so you have to repeatedly click to attack your opponent. And then maybe have an option of switching between auto-attack and manual attack.

So does anyone have any idea how to do that? I've tried to figure it out, but nothing I've done works.

Remake the whole attack system, just have attack-less heroes with an attack button that is actually an ability.

Ah... I didn't ever think about that.

But if I do it that way, then how do I switch between auto-attack and manual attack?
.... Unless I make it an auto-cast ability...

But then it won't change the amount of damage the hero does when he increases in level, and any items he's carrying won't affect his attack damage. Plus, I don't exactly see how to make it so that right-clicking an enemy will cast that ability/make him attack.

How would you change the right-click order than?

Aren't there triggers that make it so you can set a specific button to perform an action when pressed? Could you do that with the mouse?

You detect the "smart" order and change it to the dummy attack?

So... uh... what does that mean? I'm really stupid.