title: Append to String at certain position
body: <p>I have a String miscFlag which is of size 100. I need to append to this miscFlag starting from  index 20 as 0-19 are reserved for some other info. And then append subsequently at certain positions only. Can we do this using StringBuilder/StringBuffer?</p>
  
  <p>This is how i am trying to do it..</p>
  
  <pre><code>    StringBuilder info = new StringBuilder(miscFlag);
      info.append(" ");
      info.append(Misc.toTimestampLiteral(currentDate));//append this from pos 20
      info.append(" ");
      info.append(formattedStartTime);  //append this from pos 40
  </code></pre>
  
  <p>Here i am not able to specify the position from where to append.</p>