HTML Help API syntaxHWND HtmlHelp(
              HWND    hwndCaller,
              LPCSTR  pszFile,
              UINT    uCommand,
              DWORD   dwData) ;
example:
HWND hwnd =
   HtmlHelp(
            GetDesktopWindow(),
            "c:\\Help.chm::/Intro.htm>Mainwin",
            HH_DISPLAY_TOPIC,
            NULL) ;