Reading File Outside Computer's Folder?

How do I read/write from a file outside the computer's folder on the server's file system?
I'm wanting to do something like reading a file at the path "../mazStuff/fileName.txt"
I tried everything I could think of, even shell.dir() + "../mazStuff/fileName.txt" but it seems I will always get a nil value.
So I assume I can't navigate outside the computer's folder?

Split into new topic.

No, you can't, and for very good reason.