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

  Changes a string such that the changed string can be passed to the
  strcmp function and produce the same result as passing the
  unchanged string to the strcoll function.

  Syntax:

       #include <string.h>

       size_t strxfrm(char *s1, const char *s2, size_t maxchar);