How do I Pick Spirites Within An Area

Hello. I'd like to know how to pick all objects within an area, ie, example between 3 or more coordinates? Within my layout I have a "room", ie, a wall on the left, a wall on the right, a wall above, and a wall below. I'd like to select all enemies within that "room".

How about an invisible sprite set to the required size, then just check to see whats overlapping.

spongehammer I'll try that. Thank you.