TTM_WINDOWFROMPOINT    
The
TTM_WINDOWFROMPOINT message allows a subclass procedure to cause a tooltip to
display text for a window other than the one beneath the mouse cursor.
TTM_WINDOWFROMPOINT 
wParam = 0; 
lParam = (POINT FAR *) lppt; 
 
Parameters
lppt
Pointer to a POINT structure that defines the
point to be checked.
Return Values
The return
value is the handle to the window that contains the point, or NULL if no window
exists at the specified point.
Remarks
This message
is intended to be processed by an application that subclasses a tooltip. It is
not intended to be sent by an application. A tooltip sends this message to
itself before displaying the text for a window. By changing the coordinates of
the point specified by lppt, the subclass procedure can cause the
tooltip to display text for a window other than the one beneath the mouse
cursor. 
See Also