BodyFilePath in web_custom_request for webservices

Hi,

I have a webservice to test using Loadruuner. The service accept 3 inputs where 2 of them are simple string and 3rd is very large xml. The script works in web_service_protocol using wsdl, however need to read and save the xml file content in LR variables to pass it as input.

How can I implement the same using web_custom_request with BodyfilePath? In this case I want to pass the xml file path instead of reading content and saving in variable. But how to implement it when the input is key value pair  as highlighted below:

web_service_call( "StepName=ServiceName",
        "SOAPMethod=MyMethod",
        "ResponseParam=response",
        "Service=WSService",
        "ExpectedResponse=SoapResult",
        "Snapshot=t1464259761.inf",
        BEGIN_ARGUMENTS,
        "Input1=ABC",
        "Input2=DEF",
        "InputString={XMLcontent}",                                             //XML is upto 8MB large file
    END_ARGUMENTS
        BEGIN_RESULT,
        "return=Param_return",
        "return/conditions=Param_conditions",
        "return/conditions/*[1]=Param_statusCondition",
        END_RESULT,
        LAST);

Please let me know how to implemnt this in custom_request. Thanks in advance. 

Thanks,
Lakshmi