title: Extract substring in R using grepl
body: <p>I have a table with a string column formatted like this</p>
  
  <pre><code>abcdWorkstart.csv
  abcdWorkcomplete.csv
  </code></pre>
  
  <p>And I would like to extract the last word in that filename. So I think the beginning pattern would be the word "Work" and ending pattern would be ".csv". I wrote something using grepl but not working.</p>
  
  <pre><code>grepl("Work{*}.csv", data$filename)
  </code></pre>
  
  <p>Basically I want to extract whatever between Work and .csv</p>
  
  <p><strong>desired outcome:</strong></p>
  
  <pre><code>start
  complete
  </code></pre>