Finding the window under a point

[cornell@unix1.cs.umass.edu (Matthew Cornell)]

I need to know the window under a point. I can't use
find-view-containing-point as I don't have a view to pass it. I could
use #_FindWindow but how do you convert from the returned wptr to an
MCL window instance? Alternatively I could just cycle through
(windows) and return the first that answers point-in-rect-p using its
PortRect.

I'd appreciate hearning any cleaner ideas!

matt