Yeah, I also don't understand your question. If you are asking how to refer to two instances of the same object in one event, you can do this with IID, for example:
distance(Sprite(5).ImagePointX(1), Sprite(5).ImagePointY(1), Sprite(7).ImagePointX(1), Sprite(7).ImagePointY(1))
Where 5 and 7 are IIDs of two instances.
Another trick is to use a family. Create a family with this sprite and then you can pick 1 object instance and 1 family instance in the same event and access both instances separately.