This example calls WinWindowFromPoint to find out if any main windows are beneath point 100,100.

#define INCL_WINWINDOWMGR
#include <OS2.H>
HWND hwndunderneath;
POINTL point = { 100L, 100L};
hwndunderneath = WinWindowFromPoint(HWND_DESKTOP,
                                    &point,
                                    FALSE); /* do not test the */
                                            /* descendants of  */
                                            /* the main        */
                                            /* windows.        */