This function returns the pointer position.

#define INCL_WINPOINTERS /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HWND       hwndDeskTop;  /*  Desktop-window handle. */
PPOINTL    pptlPoint;    /*  Pointer position in screen coordinates. */
BOOL       rc;           /*  Pointer position returned indicator. */

rc = WinQueryPointerPos(hwndDeskTop, pptlPoint);