Hi Michael T.

My amateur answer:

This would be very easy to do.
Code extracted from existing scripts:

var pointpicker = moi.ui.createPointPicker();

if ( !GetPoint( pointpicker ) )
return;

var PickedPt = pointpicker.pt;

Then do an Alert with
PickedPt.X
PickedPt.Y
PickedPt.Z

It would probably take me an hour, or a week :-)

- Brian