title: Replace end of line for lines that start with a particular pattern
body: <p>I have a file in the following format</p>
  
  <pre><code>--Some-XYZ-code ;
  --Somemore--xyz--code;
  COMMENT = " THIS IS A DEMO"
  --somemore--code;
  --somemore--code;
  </code></pre>
  
  <p>I want to put an semicolon at the end of line COMMENT, keeping the rest of the line intact.</p>