This function queries the window size and position of a visible window.

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

HWND    hwnd;  /*  Window handle. */
PSWP    pswp;  /*  SWP structure. */
BOOL    rc;    /*  Success indicator. */

rc = WinQueryWindowPos(hwnd, pswp);