creating control points for a point cloud alignment/AT alignment.

Hi, I recently read about creating Control Points to make Fake GCPs to align a AT to a point cloud. I am unsure how to add the control points to a point cloud. I have used the process to merge ATs, but since there aren't any photos in the point cloud or match ones I could create in the AT. I am unsure how to define points in the point cloud. In the 3d window the point cloud is only selectable as a whole and not individual points.

Any guidance would be very much appreciated.