SOAPMessage Workflow Activity

I am setting up a workflow to call a webservice using the SOAPMessage activity. The webservice takes a list as a request parameter i.e.

<oneList><one>abc</one><one>def</one></oneList>

The wiki says ' Variables to substitute into the SOAP Envelope defined in the SOAP Message Function record. This string should be in the format name1=value1, name2=value2, .

Now, in this case, how do I pass the parameters?