MCOPY

        [MRTCAL\]MCOPY IndexFile

    Copy the current index (from memory) to the given file  (to  disk).  Any
    pre-existing  file  is  overwritten. This command is useful for two main
    purposes:
      - extract a subset from an index file, by combining the commands INDEX
        OPEN, MFIND (with criteria), and MCOPY, or
      - merge  several  index  files,  by combining INDEX OPEN, INDEX APPEND
        (repeated), MFIND, MCOPY.