This function creates a secondary window from a dialog template in memory.

#define INCL_SW
#include <os2.h>

HWND            hwndParent;     /*  Parent window handle. */
HWND            hwndOwner;      /*  Window-handle owner. */
PFNWP           pfnDlgProc;     /*  Secondary window procedure. */
PDLGTEMPLATE    pdlgt;          /*  Dialog template. */
PVOID           pCreateParams;  /*  Parameters passed to secondary window proc. */
HWND            hwnd;           /*  Window handle. */

hwnd = WinCreateSecondaryWindow(hwndParent,
         hwndOwner, pfnDlgProc, pdlgt, pCreateParams);