The following code illustrates returning a window handle to various windows created as a part of a secondary window.

  #define INCL_SECONDARYWINDOW
  #include <sw.h>

  HWND hwndFrame, hwndDialog;

  hwndFrame = WinLoadSecondaryWindow (HWND_DESKTOP, /* Parent window */
                                      HWND_DESKTOP, /* Owner window  */
                                      MyDlgProc,    /* Dialog proc   */
                                      NULL,         /* Module handle */
                                      ID_DIALOG,    /* Resource ID   */
                                      NULL);        /* Create params */
  hwndDialog = WinQuerySecondaryHWND( hwnd, QS_DIALOG );