Body parts to attach stuff to (trigger question) and doodad properties question

You all know the trigger to use to make the exclamation mark pop up over someone's head, right? Well, it basically says to put [a model] to [something on the map, I think it only works with units]
on the OVERHEAD...now this is the question : What other things work besides overhead, I was looking for something lower, like body or feet or mesh or waepon or something, but since there is no menu to pick from I had to guess possible values...nothing yet so far... any ideas? (to put it really short : If I want to make an exclamation mark appear inside the unit mesh, what value should I replace OVERHEAD with in the trigger that attaches animations to units.)

Also, can you edit the properties of doodads? Like the collision size (not the size they are automatically given when you rescale them, but I'd like to try and add the same "properties" buildings have to a doodad...an example : No matter how close together you build, your units will always be able to squeeze between the structures... ok, you can totally block an area with some structures, but you know what I mean, the pathing is smaller than the footprint, so there is some spacing - If I gave this to trees, units would be able to walk through a denser forest, and the big brush wouldn't place trees as close together as it does now).

And finally...how do I use doodads for structures and vice versa (the models I mean)....

well...did some more research...can add something now : "chest"works...I found this after looking at the body part rotation thingy for cinematics. It's a start. (of course, head will work too then...). Kinda sweet to make custom "spells"... All cross your fingers I finish my maps (got like a dozen plans...all heavily relying on special gimmicks...call em mod maps if you like...shut up Rygir before someone thinks you're bragging)

Thanks! Mind telling me where you found this information? (so I won't have to ask questions like this again...

Ooh, thanks. I was just about to ask that same question.