I need some trigger help

For my map i was wondering if it would be possible to take all the remaining heros and allow 2 of them to be randomly selected to be placed into a certian area. The trigger would be something like.
When owner of triggering unit enter a region, create 1 random hero and 1 different random hero,
The heros cannot be the same as each other or the player that that entered the area

im not following what your saying?
somethign like this?
when hero X enters area A
create hero Y, different from hero X, at region B
create hero Z, differnt from hero X and Y, at region C
? like that ?

sorta,
its like when player x enters region a, create player y at region a and create player z at reigion a
where x y and z are all different and contolled by different players such that x is controled by p1 y by p5 and x by p9