title: From a varchar column extract the last two digit seperated by '-'
body: <p>I have a Dataframe like below</p>
  <pre class="lang-none prettyprint-override"><code>COURSE_KEY.           
  INC-AAB-WW-123456    
  INC-AAB-NL-104514
  </code></pre>
  <p>I need to fetch the numerical digit and the code before that. so that the data looks like below</p>
  <pre class="lang-none prettyprint-override"><code>COURSE_KEY
  WW-123456
  NL-104514
  </code></pre>