How do I check for an unloading unit?

Is there any possible way to check if a unit has unloaded, and the store that unit to a variable? Say I want to know if a unit has just come out of a burrow and give it an order, is there any way of checking that?

I looked through all the triggers, saw no easy way of doing it. So I made it so any loaded unit would be added to a unit group, and whenever any unit entered the map, it would be checked to see if it was in that unit group. Unfurtonately, when a unit loads into a burrow, it doesn't appear that they actually leave the region, so they can't enter it (as they are already in it).

I'm suspecting there is a JASS trigger, or something in one of the custom WE's that allows for this, and either of those solutions would be OK.

Any help would be appreciated.

Yeai know a way to do it if your still intrested just message back here and i'll post the way i just don't wanna waste my time otherwise

coolaboy, thanks for responding but I just abandoned the idea. It wasn't even for a map, I just wanted to know if it could be done, and just do some random things with it. But thanks anyways!