Yeah, you would need to use Lua script to sort that out. I can't explain how to sort out checking if 2 shapes overlap each other off the top of my head, so you will have to do a bit of googling to find some examples of collision detection done with Lua, then you will have to edit the code to make it work in Visionaire.
Quick note: the engine does have a built in function (via scripting) for checking if a point (x, y) is inside of the object area of a scene object, character, etc. but that only checks a single point.