title: how to append a query string to error document
body: <p>Is there any to to capture query string and append it to error document (404). Something like:</p>
  
  <p>Requested page:</p>
  
  <pre><code>http://www.example.com/sdsdsd
  </code></pre>
  
  <p>Redirect to:</p>
  
  <pre><code>http://www.example.com/404.php?pg-name=sdsdsd
  </code></pre>