Thanks Fritz and Christian,
Now I see that I missed the "DOS" parameter and this is why I got the error message, CANNOT SHELL OUT, ERROR #2.
I am reformulating Fritz's explanation: that is to say, this error message means that Vedit can not find a Command Interpreter. It is certainly nice to put this error message in a more general context. Now I understand that the "DOS" parameter means that my Command Interpreter is an additional copy of DOS. Incidentally, I was looking at Chapter 9, Error Messages, but could not find this one. Now I can annotate this .pdf file.
Actually, the System("dir",DOS) is only a model problem.
My original problem is something like System(File_Mkdir, "12..21)",DOS) I say something like this, since I have to study the File_ family of commands. This remind me, this is a very delicate family of commands. I had some trouble with it before, and I remember Ted's joke about it. Then webboard got upgraded and we lost some questions, including mine.
Am I the only one who uses the File_Mkdir command and has some problems?