title: Excel: if duplicate cell value found in another column then highlight green
body: <p>Can someone help me, I'm not sure what formula to use.</p>
  
  <p>I have highlighted the cell in the picture to show an example of what I mean.</p>
  
  <p>What I want to do is highlight the cell in column A where the value matches a value in column D, it does not have to be in the same row. If there is a duplicate value in column D then highlight the cell in column A green.
  <img src="https://i.stack.imgur.com/1c0Px.jpg" alt="enter image description here">
  Thanks for any help given.</p>