This function is issued by an application to post a message to another application with which it is carrying out a dynamic data exchange conversation with a national language conversation context.

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

HWND          hwndTo;     /*  Window handle of target. */
HWND          hwndFrom;   /*  Window handle of originator. */
ULONG         usMsgId;    /*  Message identifier. */
PDDESTRUCT    pData;      /*  Pointer to the DDE control structure being passed. */
ULONG         ulOptions;  /*  Options. */
BOOL          rc;         /*  Success indicator. */

rc = WinDdePostMsg(hwndTo, hwndFrom, usMsgId,
       pData, ulOptions);