title: Excel Vlookup with C#
body: <p>I am trying to use WorksheetFunction.VLookup but I get the message:</p>
  
  <p>"VLookup method of WorksheetFunction class failed"</p>
  
  <p>my code:</p>
  
  <pre><code>Excel.Range xlRange = (Excel.Range)xlWorksheet.get_Range("3:1", "333:20");
  label4.Text = xlApp.WorksheetFunction.VLookup("MAF0510530146", xlRange, 7, false);
  </code></pre>
  
  <p>do you have any idea what went wrong?</p>
  
  <p>the input string "MAF0510530146" is in the excel file...</p>
  
  <p>Thanks</p>