Hi I'm me again. I write an small patch that can be added to the "magic" file, with some "magic numbers" to identify the type of file, using of course the program file(1), just typing,
file lv_application_file
where lv_application_file is any, almost, LV file, *.vi's, *.llb's, *.mnu's.
You may also note interesting the way that follow to do this, I attach the files that I made.