difficutly implmenting drag and drop from listbox to subplot (from a program)

I'm working on a GUI program where I'll select variables from a list box and drop them onto the axis (x or y) of one of several sublots.

I've found that the listbox intercepts the figure WindowButton Up/Dn callbacks (even when the button release is outside of the listbox). This seems to make drag and drop gesture detection next to impossible.

I've noticed that just after the listbox Callback is called (on button release) there is a figure WindowButtonMotionFcn callback. Possibly I could use the hObject.Position from the first WindowButtonMotionFcn event following a listbox Callback.

Is there a better way to do this? I've seen a Java Hack in an old thread, ut its not working in my version 2014B.