title: Middleware with dynamic mount point?
body: <p>I would like to serve static assets for paths that <strong>begin</strong> with an cache buster: </p>
  
  <ul>
  <li>example.com/40/app.js </li>
  <li>example2.com/5/hello/hello.js</li>
  <li>example2.com/60000/hello/world/some-file.js</li>
  </ul>
  
  <p>Does Express support this?</p>
  
  <p>I attempted to create a custom middleware that</p>
  
  <ul>
  <li>creates a copy of the request object </li>
  <li>strips the cache buster from req.path</li>
  <li>passes the new req object to express.static</li>
  </ul>
  
  <p>but this doesn't seem to work. It appears Express.static doesn't inspect req.path directly.</p>
  
  <p>What's the best way to achieve this? Any help would be appreciated. Thanks.</p>