title: Regular Expression to find a string included between two characters while EXCLUDING the delimiters
body: <p>I need to extract from a string a set of characters which are included between two delimiters, without returning the delimiters themselves.</p>
  
  <p>A simple example should be helpful:</p>
  
  <p><strong>Target</strong>: extract the substring between square brackets, without returning the brackets themselves.</p>
  
  <p><strong>Base string</strong>: <code>This is a test string [more or less]</code></p>
  
  <p>If I use the following reg. ex.</p>
  
  <pre>\[.*?\]</pre>
  
  <p>The match is <code>[more or less]</code>. I need to get only <code>more or less</code> (without the brackets).  </p>
  
  <p>Is it possible to do it?</p>