title: Filter based on starting letter and presence of an asterisk in column
body: <p>I have a large data frame, with 22 columns. I want to filter based on values in the second column, so if the value doesn't start with "X" I want to remove that row. Also I want to remove the row if this value in the second column contains an asterisk.</p>
  
  <pre><code>test &lt;- c(1, 2, 3, 4, 5, 6, 7, 8, 9)
  secondcolumn &lt;- c("Xidfhsfd*isjdf", "Hsuhdfskdh", "Xwidfsoid", "X*sdkfjjhsd", "Xkdsfhsd", "Uskesfudhsk", "Sdfukhsdiu", "Osdfihsdoiuh", "Xsodifdsifj")
  othercolumn &lt;- c(3, 5, 7,2, 5, 8, 3, 0, 5)
  
  df &lt;- as.data.frame(test, secondcolumn, othercolumn)
  </code></pre>
  
  <p>How would this be done? In this example, I would want to remove the 1st, 2nd, 4th, 6th, 7th, 8th, and 9th rows. </p>
  
  <p>Thanks!</p>