title: get files list in a specific subfolder
body: <p>I am trying with no success to get a list of files in a .csv (and relative properties) recursevely just in one subfolders.
  This is my situation:</p>
  
  <pre><code>Root
  |
  | - Folder 1
  |   | - xxxxxx
  |   | - yyyyyyy
  |   | - INTERESTED_FOLDER  (that contains files requested)
  |
  | - ...
  |
  | - Folder n:
      | - xxxxxx
      | - yyyyyy
      | - INTERESTED_FOLDER (that contains files requested)
  </code></pre>
  
  <p>Examples I found on web talk about getting all files names in ALL subdirectories, when I'd need to search just in one but iterate for all root folders 1-n.
  Thanks for your help.</p>