/sys$common/syshlp/helplib.hlb CC, Run-time functions, vfwprintf  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Writes output to a specified file in wide character format.

  Syntax:

        #include <wchar.h>

        int vfwprintf (FILE *stream,
                       const wchar_t *format,
                       va_list arg);