It depends on what you want to attack with.
If you want to use a ranged attack and you've got a bow or crossbow equipped, just right-click on any enemy in range.
If you want to use a melee attack, you do the same thing, but you have to manually move your character right next to whatever you want to attack ("melee range" as it were). Your character will not dash towards whatever you click on by itself.
If you want to use a magic attack, switch to another camera view. Trust me, it's just not worth the hassle.
Post edited July 20, 2009 by Prator