This function sets the window text for a specified window.

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

HWND    hwnd;       /*  Window handle. */
PSZ     pszString;  /*  Window text. */
BOOL    rc;         /*  Success indicator. */

rc = WinSetWindowText(hwnd, pszString);