title: Find duplicate in excel column and show corresponding cell value
body: <p>I am attempting to use excel functions to find the value of the corresponding value of a cell of which has a duplicate within a column. That is, if value of B2 appears 2 times in column B, say B4, I am to find the value of A4. I have the following sample data for clarity:</p>
  
  <p>A, B</p>
  
  <p>123, 1.2.3.4</p>
  
  <p>321, 2.2.2.2</p>
  
  <p>111, 3.3.3.3</p>
  
  <p>678, 1.2.3.4           </p>
  
  <p>As "1.2.3.4" appears twice, I will like to display value of A4 which is "678".</p>
  
  <p>I have the following on hand, seems to be able to pick up duplicates but I got stuck on using VLOOKUP to pull the value of the corresponding cell.</p>
  
  <pre><code>IF(COUNTIF(B:B,B4)&gt;1, VLOOKUP(B4,A:B,1),FALSE), "False")
  </code></pre>
  
  <p>I try only using the VLOOKUP function but it returns a "N/A" error.</p>
  
  <p>Regards,</p>