title: Manipulate RegEx matches for computations in C#
body: <p>In C# it is easy to use RegEx like this</p>
  
  <pre><code>string pattern = "Version\\(\"(\\d+).(\\d+).(\\d+).(\\d+)\"\\)";
  Regex rgx = new Regex(pattern);
  string output = rgx.Replace(someInput, "Version $1.$2.$3.$4");
  </code></pre>
  
  <p>However I want to know how extract <code>$3</code>, increment it and write it back to the output. This is necessary for automated incrementation of the build number in my current project. I saw something concerning delegation of an evaluator but didn't read it in detail.</p>