I understand that if I have a ranged attacker on elevated terrain (say Vet Mandarin at the edge of the building), that I can "see over" hindering terrain on a lower elevation...So this would mean that I could successfully see and attack that Vet Psylocke hiding behind some trees....My question is, does this "bonus" also allow me to hit stealthed figures who are standing in a square of hindering terrain?? (Say the same Vet Psylocke standing on a dumpster in the middle of the map??) Thanks guys!!!

No. You still count the square that the target is standing in, even when they are in hindering terrain.

Does this help?

The only terrain you would have to account for when firing from Elevated to grounded... is the terrain that the grounde figure is currently occupying...

So a stealthed figure in a square that conatined Hindering terrain would not be able to be seen.

When a Stealthed figure 1 square behind a square that conatined Hindering terrian would be able to be aseen.

Sorry, do you mean "No" I can't hit her, or "No" I can?? I was leaning towards not being able to hit, since theoretically she could be hiding in the dumpster, or in the bush, but I just want to know for sure...

Thanks Tsannik!!!
(Ahhh...Took me too long to post!!)