Output based on the existence of a particular piece of data in a list

I've got the following incoming XML:

<AC:validateAcctngCodeResponse xmlns:AC="AcctngActivityWS">
  <UserId>U712345</UserId>
  <AcctngCodeOut>
        <Type>CC</Type>
        <Identifier>1234</Identifier>
        <Status>OK</Status>
        <StatusText>Document has no errors.</StatusText>
  </AcctngCodeOut>
  <AcctngCodeOut>
        <Type>P</Type>
        <Identifier>54321</Identifier>
        <Status>OK</Status>
        <StatusText>Document has no errors.</StatusText>
  </AcctngCodeOut>
  <AcctngCodeOut>
        <Type>O</Type>
        <Identifier>78960</Identifier>
        <Status>Error</Status>
        <StatusText>Order 78960 does not exist</StatusText>
  </AcctngCodeOut>
</AC:validateAcctngCodeResponse>

I need to make my output based on the existence of a <Status> tag with
"Error".  So, in the case above I want to have:
<accountcheckreply>
      <success>false</success>
      <message type="error">
         <code>1</code>
         <description>Order 78960 does not exist</description>
      </message>
</accountcheckreply>

Whereas if there were no errors in the incoming document, I would have
simply:
<accountcheckreply>
      <success>true</success>
</accountcheckreply>

I haven't been able to figure out what I need to use to make this happen.
Can anyone offer a suggestion of where to start?

Thanks,
Tripp

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