Help!!! RegEx.Replace
<p>How do i achieve this directory format using the RegEx.</p>

<pre><code>Input FileName(40 chars) : 000a2d0e62e43b0f680a6eb6019f9671b15ca291

output should looks like this: 00\0a2\d0e\62e43  
get only the first 13th character.
</code></pre>

<p>Thanks a lot.</p>

<p>johnL</p>
