title: Format a MAC address using string.Format in c#
body: <p>I have a mac address which is formatted like <code>0018103AB839</code> and I want to display it like: <code>00:18:10:3A:B8:39</code></p>
  
  <p>I am trying to do this with <code>string.Format</code> but I cant really find the exact syntax. </p>
  
  <p>right now I am trying something like this:</p>
  
  <pre><code>    string macaddress = 0018103AB839;
      string newformat = string.Format("{0:00:00:00:00:00:00}", macaddress);
  </code></pre>
  
  <p>Is this even possible? or should I use <code>string.Insert</code>?</p>