Re: drawing on a surface using pointcloud data behind

I have a pointcloud survey from which I have to produce models and elevations etc. I have created a surface at a location in front of the elevation (in this case) but have great problems with ensuring the new graphics are drawn on the flat surface.

I have tried by controlling the ACS plane and snap plane as well well as controlling the X, Y and Z coordinates but it has a mind of its own. I cannot see what I am doing wrong.
Any pointers would be of great help to me