Player selects a region

Is there any way to make it so if a player selects a region (hidden obviously) something happens? Is there any event?

You'll need to explain a little further, what kind of region? (Size etc.)

I'm not sure how you could possibly select a region in game. That doesn't seem physically possible. The only thing selectable are units and buildings... Unless you mean something else; please clarify your request.

what kind of regeon? you mean a regeon like made in world editor or a spell AoE regeon??

A WE region, as in a box about the size of a farm that will magically be moved to the lower left corner of player X's screen every .1 Second, I want to know if theres any way to make a trigger so if you click there, it triggers something.

Clear enough?

Maby you can place a unit or building in the region and then let the player select it.

That was my initial thought but it wouldnt work because of ground heights, the unit moves out of the camera view and such, plus you wouldnt be able to see it if that area of the screen were under fog of war.

The main idea is to add a button that floats somewhere specific on the screen.