Explode number string and change the format
<p>I have many strings such as:</p>

<blockquote>
  <p>"1.5.22.1.2"</p>
</blockquote>

<p>and I would need to pull it apart and put it back together again like this:</p>

<blockquote>
  <p>"1.05.22.01.02"</p>
</blockquote>

<p>The difference is that there are no leading zero for the first one.</p>

<p>This is a big, "copy, manipulate and paste" job because the strings are used as codes in one of out programs.</p>