This function returns the state of the key at the time that the last message obtained from the queue was posted.

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

HWND    hwndDeskTop;  /*  Desktop-window handle. */
LONG    vkey;         /*  Virtual key value. */
LONG    lKeyState;    /*  Key state. */

lKeyState = WinGetKeyState(hwndDeskTop, vkey);