title: Add comma every nth character in value
body: <p>my problem is pretty simple. I get a value from a sql select which looks like this:</p>
  
  <pre><code>ARAMAUBEBABRBGCNDKDEEEFOFIFRGEGRIEISITJPYUCAKZKG
  </code></pre>
  
  <p>and I need it like this:</p>
  
  <pre><code>AR,AM,AU,BE,BA,BR,BG,CN,DK,DE,EE,FO,FI,FR,GE,GR,IE,IS,IT,JP,YU,CA,KZ,KG
  </code></pre>
  
  <p>The length is different in each dataset.
  I tried it with format(), stuff() and so on but nothing brought me the result I need.</p>
  
  <p>Thanks in advance</p>