title: Subtracting columns in a Vlookup
body: <p>I have a Excel spreadsheet that has two tabs, I have data on the DATA tab and the results of the data on the RESULTS tab. On the RESULTS tab I need to create a vlookup that will look for data on the DATA tab and subtract Column A from Column B. Is this possible with vlookup?</p>
  
  <p>I have a before and after with the same clientID but data being copied/pasted will change.</p>
  
  <pre><code>Before 
  A        B      C
  1021    102    125.00
  1022    102    150.00
  1023    105    100.00
  
  After
  A       B        C
  1021   102   125.00
  1022   102   
  1023   105   100.00
  </code></pre>
  
  <p>So each day I take the AFTER number and paste them over the before number, and get my new AFTER numbers from another tab.But if the pasted AFTER number does not have data for that specific account (in this case 1022), and the new AFTER number I get from another tab does not have data for 1022, my comparision will be off an account and will not notify me that this account is missing. I'm sorry, i know that is probably confusing.</p>