ColorAtScreenLoc Function

[Ray]

Anybody know of a function which returns the color of the screen at a 
given location?  Simply pass it a point and get the color of that pixel, 
kind of like a combination of the mouseColor function and the 
controlAtScreenLoc function.  I'd be happy if it only worked for points 
on Livecode stacks.  I've tried 'click at loc [myPoint] and then getting 
the mouseColor but it doesn't work.