title: Converting Notepad++ REGEX to .NET C#
body: <p>Working with a pipe-delimited file. Currently, I use Notepad++ find and replace REGEX pattern <code>^(?:[^|]*\|){5}\K[^|]*</code> that replaces all lines with an empty string between the 5th and 6th <code>|</code>. I'm trying to programmatically do this process, but .NET does not support <code>\K</code>. I've tried a few instances of the backward lookup, but I cannot seem to grasp it.</p>
  <pre><code>string[] lines = File.ReadAllLines(path);
  foreach (string line in lines)
  {
      string line2 = null;
      string finalLine = line;
      string[] col = line.Split('|');
      if (col[5] != null)
      {
          line2 = Regex.Replace(line, @&quot;^(?:[^|]*\|){5}\K[^|]*&quot;, &quot;&quot;);
  </code></pre>