Create a unit if there are these items in a region and a unit goes to a region? HELP!

I'm trying to make it so, say, Unit Enters Region. And if there are certain ITEMS in ANOTHER region on the GROUND, it would create a unit for the owner of that unit. Can somebody help, please? >_>

Ehh...

Unit enters region

Region == X

pick every item in other region
--picked item - if picked item-type == XX then create the unit else do nothing


That will create one unit for each item in the other region.

Alternatively: picked item - if picked item-type == XX then set booleanVariable = true else do nothing

If booleanVariable = true then create the unit else do nothing
booleanVariable = false

I mean MULTIPLE items--like a Medium Hover System, Fan, Laser Cannon, Laser Cannon, and such. It's a game where you have to seek items and combine them... Thats what I cant get.