title: Regular expression - extract 6 digits exactly
body: <p>Yoav - edited to be clearer</p>
  
  <p>Hi,
  I need to find 6 digit numerical strings in a text file. I'm working in C#.
  Example:</p>
  
  <pre><code>text text text123365 text text text
  </code></pre>
  
  <p>The expression must skip strings longer then 6:</p>
  
  <pre><code>text text text1233656 text text text
  </code></pre>
  
  <p>The above string should not return any result because the length of the digit string is 7.</p>
  
  <p>I came up with this expression: <code>[^0-9]([0-9]){6}[^0-9]</code></p>
  
  <p>It works perfectly with the exception of string that are at the start or end of the line</p>
  
  <pre><code>123365text text text text text text
  text text text text text text123365
  </code></pre>
  
  <p>Is it possible to identify these cases?</p>