title: How to limit cell value in Excel to options from another sheet?
body: <p>In Excel (2003), I want to limit the selection of values in a cell to allowable values from another spreadsheet.</p>
  
  <p>For example, in the sheet "Currencies" I have</p>
  
  <pre>EUR,1.1
  GBP,1.0
  USD,1.5</pre>
  
  <p>(That's two columns, three rows)</p>
  
  <p>In my main sheet I'd like to have a Currency column, in which the only allowable values are from column A in the Currencies sheet, i.e. the cell can contain only 'EUR', 'GBP', or 'USD'.  (Elsewhere I'll be using that as a lookup to get the exchange rate, which is column B.)</p>
  
  <p>How can I restrict the value in the cell?  Having a dropdown like a windows combo box populated from the other sheet would be great.  </p>
  
  <p>Any answers using formulas, VBA, or whatever will be fine.  Even a pointer to the relevant documentation would be great (I have looked, but I'm not sure what to look for).</p>
  
  <p>Also helpful would be answers using LibreOffice, since I haven't finalized the choice of spreadsheet program, but I thought I'd have a better chance getting an answer in Excel.</p>