Trapping for mouseDown on the desktop on a Mac

[Ray]

On Windows the instant there is a 'mouseDown' on the desktop the current 
stack window goes inactive, thus triggering the suspendStack message.  I 
use this to create a field which then accepts dragDrops.  However, this 
is different on a Mac.  The current stack window on a Mac waits until 
the mouse comes up on a desktop click, thus defeating my scheme which 
creates the field to accept a dragDrop as soon as the mouse goes down on 
the desktop.

Any ideas anybody on how to trap for a mouse down on the desktop on a Mac?

Many thanks,

Ray
LinkIt! Software