My httpd.conf

<VirtualHost *:80>
    ...
    DocumentRoot /home/www/static
    ...
    <Directory /home/www/static>
    Order Allow,Deny
    Allow from all
    </Directory>

    <Location "/foo">
    SetHandler None
    </Location>
</virtualhost>

I've got a file at /home/www/static/foo/helloworld.txt. And when Time passes to http://localhost/foo/helloworld.txt I notice file.

Now, for many irrelevant reason, I wish to alter the web addresses. The above mentioned url should return nothing, while http://localhost/bar/helloworld.txt should return the file. And I wish to accomplish this, without altering anything within the directory structure.

How's so now?

You should use Alias to map different url pathways to filesystem pathways:

Alias /bar /home/www/static/foo

See http://httpd.apache.org/docs/2.2/mod/mod_alias.html#alias for more information.