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

  Converts the argument, a wide character, to uppercase.  If the
  argument is not a lowercase character, it is returned unchanged.

  Syntax:

       #include <wctype.h>  (ISO C Standard)
       #include <wchar.h>   (XPG4 Standard)

       int towupper(wint_t wc);