title: Epplus formula error
body: <p>I'm using Epplus to put a formula into a cell. If I put this formula manually into the Excel cell it works:</p>
  
  <pre><code>=SUM(E4;G4)
  </code></pre>
  
  <p>But when I put in code with Epplus it doesn't work:</p>
  
  <pre><code>xls.ActiveSheet.Cells(8, 4).Formula = "SUM(E4;G4)"
  </code></pre>
  
  <p>Is there something special needed when I SUM two cells?
  If I do the same with a range of cells it works, but with specific cells not.</p>
  
  <p>This works (Range):</p>
  
  <pre><code>xls.ActiveSheet.Cells(8, 4).Formula = "SUM(E4:G4)"
  </code></pre>