VMS Help CC, Run-time functions, iconv  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Converts characters coded in one codeset into another codeset.

  Characters in the buffer pointed to by inbuf are converted to
  characters in another code set.  The resulting characters are
  stored in the buffer pointed to by outbuf.  The conversion type is
  specified by the conversion descriptor cd.  This descriptor is
  returned from a successful call to iconv_open.

  If an invalid character is found in the input buffer, the
  conversion stops after the last successful conversion.  The
  variable pointed to by inbytesleft is updated to reflect the number
  of bytes in the input buffer that are not converted.  The variable
  pointed to by outbytesleft is updated to reflect the number of
  bytes available in the output buffer.

  Syntax:

       #include <iconv.h>

       size_t iconv (iconv_t cd, char **inbuf, size_t *inbytesleft,
       char **outbuf,
       size_t *outbytesleft);