This function adjusts the pointer display level to show or hide a pointer.

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

HWND    hwndDeskTop;  /*  Desktop-window handle. */
BOOL    fShow;        /*  Level-update indicator. */
BOOL    rc;           /*  Display-level-updated indicator. */

rc = WinShowPointer(hwndDeskTop, fShow);