This function creates a chunk in a RIFF file that was opened by mmioOpen.

#define INCL_MMIOOS2
#include <os2.h>

HMMIO        hmmio;    /*  Open file handle. */
PMMCKINFO    pckinfo;  /*  Pointer to MMCKINFO. */
USHORT       usFlags;  /*  Flags. */
USHORT       rc;       /*  Return codes. */

rc = mmioCreateChunk(hmmio, pckinfo, usFlags);