VMS Help CC, Language topics, Builtin Functions, Move Character 5 Operand  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The _MOVC5 function allows the source string specified by the
  pointer and length pair to be moved to the destination string
  specified by the other pointer and length pair.  If the source
  string is smaller than the destination string, the destination
  string is padded with the specified character.

  Syntax:

       void _MOVC5(unsigned short __srclen, const char *__src, char
                   __fill, unsigned short __destlen, char *__dest,
                   ...);

  where the ... is one to three optional arguments:

   o  unsigned short *unmoved_src

   o  char ** endscr

   o  char **enddest