This function copies window text into a buffer.

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

HWND    hwnd;     /*  Window handle. */
LONG    lLength;  /*  Length of pun. */
PUN     pun;      /*  Window text. */
LONG    lRetLen;  /*  Length of returned text not including the null terminator. */

lRetLen = WinQueryWindowText(hwnd, lLength,
            pun);