CWnd* ChildWindowFromPoint( POINT point ) const;
point
Specifies the client coordinates of the point to be tested.
Determines which, if any, of the child windows belonging to CWnd contains the specified point.
Identifies the child window that contains the point. It is NULL if the given point lies outside of the client area. If the point is within the client area but is not contained within any child window, CWnd is returned.
This member function will return a hidden or disabled child window that contains the specified point.
The CWnd* that is returned may be temporary, and should not be stored beyond its immediate use.
CWnd::WindowFromPoint, ::ChildWindowFromPoint