title: Use ClosedXML to show exponent value with use of superscript
body: <p>With ClosedXML, I need to show 10 (base) with a superscript of 2.
  As such it is an exponent value. I know I can do a subscript of 2 the following way:</p>
  
  <pre><code>            ws.Cell(2, 8).Value = 2;            
              ws.Cell(2, 8).Style.Font.VerticalAlignment =  XLFontVerticalTextAlignmentValues.Superscript;
  </code></pre>
  
  <p>But how do I show 10 which is a base in the same cell as the superscript value?
  Essentially I am trying to show 2 different styles of font in the same cell. 
  Hopefully this makes sense.</p>
  
  <p>I tried to use the following but did not get far as it show 102 instead of 2 as a superscript:</p>
  
  <pre><code> ws.Cell(2, 8).Value = 102; 
   ws.Cell(rw, 8).RichText.Substring(2).VerticalAlignment = XLFontVerticalTextAlignmentValues.Superscript; 
  </code></pre>