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

  Converts a multibyte character sequence to a corresponding wide
  character sequence.

  Syntax:

        #include <wchar.h>

        size_t mbsrtowcs (wchar_t *dst,
                          const char **src,
                          size_t len,
                          mbstate_t *ps);