Fix non-standard web serverice port on contractRef and docRef

Question

My problem is closely related to this one: http://stackoverflow.com/questions/640641/how-can-i-use-net-web-services-from-non-standard-ports. My web service runs behind a port-forwarding firewall, so the port numbers reported in the WSDL document contain the internal high-numbered port. I wrote a SoapExtensionReflector class which is able to rewrite the WSDL document. So a request like example.com/path/loginservice?wsdl is handled correctly.

However, this doesn't handle the "disco" request: example.com/path/loginservice?disco. This returns an XML document like this:

<discovery>
  <contractRef ref="http://example.com:10092/loginservice.asmx?wsdl" docRef="http://example.com:10092/loginservice.asmx"/&gt;
  <soap address="http://example.com/path/loginservice.asmx" binding="q1:LoginServiceSoap"/>
  <soap address="http://example.com/path/loginservice.asmx" binding="q2:LoginServiceSoap12"/>
</discovery>

While the soap bindings have been properly re-written by the SoapExtensionReflector, the contractRef and docRef URLs have the high-numbered port. How can I rewrite them as well?