So you said we need to have the empty at the same position as the object we want to reference it to.
Does that mean it is dependant on the 0,0,0 coordinates, or is it dependant on the origin of the object? Say my stairs are at a different location, but i place my 3d cursor on their origin and add the empty there, will it then work as intended?
Another thing, if i put the origin of the object somewhere else, but the step itself isn't moved, do i have to put the empty at the middle of the object or the origin (that has been placed somewhere else)?