Converting a SOAP string to Lisp data

Hi,

I am using ACL's SOAP API. From one particular server, the SOAP response 
that I get is rather peculiar - a SOAP envelope inside another one. i.e.

<SOAP-ENV:Envelope 
xmlns:SOAP-ENV='http://schemas.xmlsoap.org/soap/envelope/' 
SOAP-ENV:encodingStyle='http://schemas.xmlsoap.org/soap/encoding/'>
  <SOAP-ENV:Body>
    <ns1:Response xmlns:ns1='http://...'>
      <Result>true</Result>
      <A_Response>
   
    <?xml version='1.0' encoding='UTF-8'?>
    <SOAP-ENV:Envelope 
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" ...>
      <SOAP-ENV:Header>
        ...
      </SOAP-ENV:Header>
      <SOAP-ENV:Body>
        ...
      </SOAP-ENV:Body>
    </SOAP-ENV:Envelope>
   
      </A_Response>
    </ns1:Response>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

ACL preserves the inside SOAP envelope as a string - which is expected. 
But what I want to do is convert the inside SOAP envelope to Lisp data. 
How can I go about it? If I have a string containing a complete SOAP 
response, how can I convert it into lists using Allegro's API?

Thanks,
Chaitanya