title: how to display a validation list with value from two columns of another tab?
body: <p>I have a requirement where i need to apply a list validation in such a way that list should display data from two columns (of different tab in same excel) combined with "-" ?<br>
  I am able to display the single column using named range but unable to display with two columns?<br><br>
  <img src="https://i.stack.imgur.com/5Huuv.jpg" alt="First tab which has source columns"><br></p>
  
  <p><img src="https://i.stack.imgur.com/zq9Xg.jpg" alt="Second Tab which should list combined columns"><br></p>
  
  <p><br>How can we achieve this?</p>
  
  <p>Below is the problem with helper column.For new record, i do not have values in helper column.Hence, list doesn't display the new records.</p>
  
  <p><img src="https://i.stack.imgur.com/hLSjC.jpg" alt="Problem with helper column"></p>
  
  <p>Thanks in advance!</p>