title: Insert string in specific string location
body: <p>I have a text file(.txt) like this</p>
  <blockquote>
  <p>Dialogue: 0,0:00:01.99,0:00:03.84,Default,,0000,0000,0000,,Up you go!</p>
  <p>Dialogue: 0,0:00:03.84,0:00:06.31,Default,,0000,0000,0000,,And, again!</p>
  <p>Dialogue: 0,0:01:42.92,0:01:44.91,Default,,0000,0000,0000,,Hang on a minute.</p>
  </blockquote>
  <p>I want to insert &quot;{&quot; and &quot;}&quot; into that file like this</p>
  <blockquote>
  <p>Dialogue: 0,0:00:01.99,0:00:03.84,Default,,0000,0000,0000,,{Up you go!}</p>
  <p>Dialogue: 0,0:00:03.84,0:00:06.31,Default,,0000,0000,0000,,{And, again!}</p>
  <p>Dialogue: 0,0:01:42.92,0:01:44.91,Default,,0000,0000,0000,,{Hang on a minute.}</p>
  </blockquote>
  <p>I mananed to insert &quot;}&quot; to the last using these code</p>
  <pre><code>            String path = openFileDialog1.FileName;
              List&lt;string&gt; line = new List&lt;string&gt;();
              StreamReader sr = new StreamReader(path);
              StringBuilder sb = new StringBuilder();
              String lines;
  
              while ((lines = sr.ReadLine()) != null)
              {
                  line.Add(lines+&quot;}&quot;);
              }
  
              foreach (string s in line)
              {
                  sb.AppendLine(s);
              }
  </code></pre>
  <p>I want to insert &quot;{&quot; right after &quot;0000,,&quot; . Sorry for my Eng and Thank you for your help.</p>