algorithmic modeling for Rhino
I have come across the same problem. I guess it is a little bit tricky to create a GH-panel to place a 3D point on a 2D workspace.
However, the MD-Slider works on an XY-Plane. If you need to apply the MD-Slider in an XZ-Plane or YZ-Plane, you can fine a solution in the attaches file!
Sorry, the 3D mode doesn't work yet. Never got around to writing it.
i can't believe the easy way to do this, thanks for sharing!