Easier way to Call a SOAP Service with Many Parameters? - wcf

Question

My web services are rusty so I hope I'm just missing something kind of obvious.
I have a WCF service that, in part, relays calls it receives to a third party SOAP service. The service receives an object that matches the body of the SOAP message that needs to be sent.
I've added a service reference based on the SOAP service's WSDL to the project and created and instance of the service proxy class. The service method I want to call has 30+ parameters.
I could call it with MyService.TheMethod(obj.value1, obj.value2, obj.value3...), but it would be nice to just pass the original object on or XML serialize it and pass the XML as a body.
Is there something that would allow an easier approach or do I need to individually pass obj's properties onto the SOAP method?
UPDATE
Clarifying the underlying issue.
My .NET service accepts something "Group"
public class Person { string Name; int Age;}
public class Group { string Name; Person[] Individuals; }
I then need to call the third party web service (TPWS). The proxy class generated from the WSDL winds up like:
public class WSPerson { string Name; uint Age;}
public class WSGroup { string Name; WSPerson[] Individuals; }
I'd been doing earlier prototyping and working with the TPWS through SoapUI and using tags matching my original (.NET) classes' naming:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ws="http://ws.myabc123.com" xmlns:ns="http://schemas.datacontract.org/2004/07/" xmlns:sys="http://schemas.datacontract.org/2004/07/System" xmlns:arr="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
<soapenv:Header>
<ws:ServiceCredentials>
<ws:SubscriberId>ABC</ws:SubscriberId>
<ws:SubscriberUser>Joe</ws:SubscriberUser>
<ws:SubscriberPassword>12345</ws:SubscriberPassword>
<!--Optional:-->
<ws:SubscriberIdentityStore></ws:SubscriberIdentityStore>
</ws:ServiceCredentials>
</soapenv:Header>
<soapenv:Body>
<Group>
<Name>Cool People</Name>
<Individuals>
<Person>
<Name>Tom</Name>
<Age>25</Age>
</Person>
<Person>
<Name>Jane</Name>
<Age>27</Age>
</Person>
</Individuals>
</Group>
</soapenv:Body>
</soapenv:Envelope>

Answer 1

There's no easy way to do what you want. If the service you're calling has 30 parameters, you'll just have to call it with 30 parameters.

Answer 2

Perhaps this will help others. I'm pursuing the idea of calling the web service through HTTP POST.
The reason is that this general problem will be repeated in similar ways over and over. I control the incoming data contract and the format of the XML that the 3rd party mapping tool ultimately expects. But it generates its own contract for the service. If it can recognize the raw XML that I can produce through XmlSerializer I won't have to map my class just to get the 3rd party tool to in turn perform its own mapping functions.