title: Copy one file every 5 files from a folder to another one using MATLAB
body: <p>I would like to copy some files from a folder to another folder using MATLAB routines. My goal is to copy one file every 4 files from the initial folder to the second one.
  My files look like this:</p>
  
  <pre><code>aa-dd-cc-11-01.txt
  aa-dd-cc-11-02.txt
  aa-dd-cc-11-03.txt
  aa-dd-cc-11-04.txt
  aa-dd-cc-11-05.txt
  aa-dd-cc-11-06.txt
  aa-dd-cc-11-07.txt
  aa-dd-cc-11-08.txt
  aa-dd-cc-11-09.txt
  </code></pre>
  
  <p>And I would like to copy in the second folder, only:</p>
  
  <pre><code>aa-dd-cc-11-01.txt
  aa-dd-cc-11-04.txt
  aa-dd-cc-11-08.txt
  </code></pre>
  
  <p>where <code>aa-dd-cc-11-08</code> is the file name and <code>.txt</code> is the extension</p>
  
  <p>could you help me to write a routine for this, please? thank you in advance</p>