title: get last 6 characters of a match (javascript regex)
body: <p>I am trying to parse txt files with js + regex and my problem is as follows:</p>
  
  <p>I have multiple txt files, and inside each one I need to search for an Id, made by 6 characters (numb + letters)</p>
  
  <p>this is the string inside one of those files:</p>
  
  <pre><code>**IFCPROPERTYSINGLEVALUE('codice sito',$,IFCTEXT('I013FR'),$);**
  </code></pre>
  
  <p>I need to extract the <strong>I013FR</strong> only, and so far the closest js-regex I wrote is:</p>
  
  <pre><code>(codice sito',\$,IFCTEXT\('[a-zA-Z\d]{6})
  </code></pre>
  
  <p>using that, I get in return:</p>
  
  <pre><code>codice sito',$,IFCTEXT('I372TO
  </code></pre>
  
  <p>now I need to "add something" at the end of the regex, in order to only take the last 6 characters from the match. </p>
  
  <p>Is that possible? am I on the right way? or maybe there is another better way to do that?</p>