title: YAML Config - best way to replace symbols within a string
body: <p>I have a configuration file in YAML format with some paths in my rails applications like this:</p>
  
  <pre><code>config
      :path1: /a/b/c
      :path2: /a/:id/c
  </code></pre>
  
  <p>path1 doesn't helps too much. I need that every time I use config[:path2] to somehow replace the :id with a value I have. It is possible?</p>
  
  <p>Hope this was clear enough.
  Thanks!</p>