title: htaccess url rewriting to sub directory without changing the addressbar
body: <p>Hello I would like to achieve the following, but i'm not sure if it's possible with .htaccess and/or how to do so.</p>
  
  <pre><code>http://domain/admin/rest should go to http://domain/backend/www/rest
  http://domain/rest should go to http://domain/frontend/www/rest.
  </code></pre>
  
  <p>but preferably without changing the url in the address bar.
  rest can be anything like 'news/1/'.</p>
  
  <p>If it's not possible in .htaccess, please point me in the right direction.</p>