title: Powershell - trying to compare-object of two columns and write difference
body: <p>Hope you can help !  I’ve been trying to use the compare-object command with various degrees of success but nothing like what I need.  I'm beginning to think maybe compare is not the answer.</p>
  
  <p>I have two CSV files: RESULTS1 and RESULTS2</p>
  
  <p>RESULTS1 has several columns with headers...</p>
  
  <pre><code>DATE DAY    LETTER  CAR         NUMBER  NEW
  </code></pre>
  
  <p>RESULTS2 has two columns with headers…</p>
  
  <pre><code>CAR COLOUR
  </code></pre>
  
  <p>This is the output I’m trying to achieve…  Using the column CAR only, identify the cars from RESULTS1 and remove them (as duplicates) from the column CAR in RESULTS2 (ie. if Ford is listed in both CSV's, don't show it in the output).  The output will list the remaining cars from the CAR column.  I still need to print (as an output CSV) the four columns as below…  (or the very least, todays date, day and CAR).</p>
  
  <pre><code>DATE        DAY  LETTER CAR
  </code></pre>