I have a file to which the user has access, but he has no folder permission to

It is possible for a user to navigate to a file for which
he does not have folder permission. This involves simply knowing the path of the
file object. Even if the user can’t drill down the file/folder tree using My
Computer, he can still gain access to the file using the Universal Naming
Convention (UNC). The best way to start would be to type the full path of a file
into Run… window.