title: Rewriting a number based URL using .htaccess RewriteRule
body: <p>How can I rewrite a simple number based URL to a sub folder?</p>
  
  <p>I want <a href="http://mysite.com/123" rel="noreferrer">http://mysite.com/123</a> to redirect to <a href="http://mysite.com/en/123" rel="noreferrer">http://mysite.com/en/123</a>.</p>
  
  <p>The number could be anything from 1 - 9999. My attempt in htaccess was:</p>
  
  <pre><code>RewriteRule ^([0-9]+)$ /en/$1/ [R]
  </code></pre>
  
  <p>But that doesn't work.</p>