I want to make an artillery unit that continually attacks but to only one location, then, if necessary, "rotated" by a certain degrees by a "crank" next to the artillery.. The only way I can think of doing it is by using a grid-type function. But with SC2 I wondered if there could be some new way.

How are you planning on implementing this? I think you could have an artillery unit with four "clickable" around it, and then create a trigger with the even "Unit is clicked", with the unit being the four movement units (cranks) around it. Each one would move a region a respective way, and the unit would always be ordered to fire upon that region. Of course, you'd also have to create an attack that targets an area, and not a unit. Or you could make the attack splash and target a dummy unit to splash damage everything in the region.

However, this might create some abnormalities, as the region would have to move by a certain amount each way, so anything in between steps wouldn't be targetable. A way around that may be to play with a sine/cosine function to get a correctly scaling region movement.

I dunno, if you elaborate a bit more maybe we can come up with something better. It's just a little vague right now.