AutoCad :: Moving 2D Object To 3D Position Through Association / Searching

I have a 2D plan and a 3D plan. The data is essentially the same on both, the only difference being that the 2D plan has several hundred points on it (all at elevation/z coordinate of 0, of which can easily be copied to the 3D plan).

I want to move those 2D points to their respective 3D positions. I.e. if point X is at coordinates 15213.321, 51646.632, 0 I would like to search in the Z direction above (or below; although in this data set it would always be above) for any object (line, polyline, 3dpolyline or an arc only I think) that crosses or is on this coordinate and then move the point (or place a new point) to that z coordinate. So if there is a line whose z value is 895.265 at coordinate 15213.321, 51646.632, then the point (that was originally 2D) would become 15213.321, 51646.632, 895.265.

Any lisp or other method in AutoCad that could accomplish this (ideally without having to select each point individually)? Surely this must have come up a few times before although I'm not too sure what search words to be using to look for info.