DosSetFileMode

#define INCL_DOSFILEMGR

USHORT  rc = DosSetFileMode(FileName, NewAttribute, Reserved);

PSZ              FileName;      /* File path name string */
USHORT           NewAttribute;  /* New attribute of file */
ULONG            0;             /* Reserved (must be zero) */

USHORT           rc;            /* return code */