Consuming web service from Excel (VBA)

Is it possible (and if so do you have any guidance) to consume a Pipeline Pilot web service (v7.5) directly from Excel using VBA and SOAP ?

I tried to use an existing protocol (the "compute Statistics" example) from Excel using the MS Soap Library (v3) but get an error "The operation ListMethods had an invalid parts attribute HRESULT=0x8000\$005" when trying to initialize the client using the WSDL for the protocol.

Do you know whether PP web services can be consumed by this client, and if not what would be the best approach for running a PP web service from Excel ?

Thanks
Tim Williams