This function returns the physical key state.

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

HWND    hwndDeskTop;  /*  Desktop-window handle. */
LONG    sc;           /*  Hardware scan code. */
LONG    lKeyState;    /*  Key state. */

lKeyState = WinGetPhysKeyState(hwndDeskTop,
              sc);