Data driven testing

Hi,

i'm new to SoapUI,my requirement is to pass different values in my xml request,
For Example..

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:web="http://www.webserviceX.NET/">
<soapenv:Header/>
<soapenv:Body>
<web:ConversionRate>
<web:FromCurrency>EUR</web:FromCurrency>
<web:ToCurrency>USD</web:ToCurrency>
</web:ConversionRate>
</soapenv:Body>
</soapenv:Envelope>

In the above xml,i need to pass different values in from currency (otherthan EUR) and To Currency(other than USD),
could you please explain or illustrate with example and the screen shots..