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

  Converts a sequence of multibyte characters into a sequence of
  corresponding wide-character codes.

  Syntax:

       #include <stdlib.h>

       size_t mbstowcs(wchar_t *pwcs, const char *s, size_t n);