title: How can I express NaN values in Excel?
body: <p>I'm writing a .NET program which generates an XML document that is opened in Excel.  The cell's typically look like:</p>
  
  <pre><code>    &lt;ss:Cell&gt;
        &lt;ss:Data ss:Type="Number"&gt;123&lt;/ss:Data&gt;
      &lt;/ss:Cell&gt;
  </code></pre>
  
  <p>But occasionly the value I'm writing has either NaN, DIV/0, or INF.  In these cases 123 would be replaced by that text value and Excel won't open the file because of the text.</p>
  
  <p>I don't think Excel has constants, so I'm unsure of how to handle this siutation, other than put a "-1" value in instead.  Any suggestions?</p>