Modify soap:header when adding TestSteps via WsdlTestRequestStepFactory

I was able to resolve using the following to replace the current generated custom soap header with one populated by from DataGen. Im not able to generate test cases with much of the common testing stuff I need, now for the rest

def holder = groovyUtils.getXmlHolder(currentRequest.getRequestContent())
def xmlUtils = new com.eviware.soapui.support.xml.XmlUtils();
def dNode = holder.getDomNode("//ns:RequestHeader")
holder.removeDomNodes(xmlUtils.createXPath(dNode))
holder["//soapenv:Header"] = RequestHeaderExpansion
wsdlTestRequestStep.getTestRequest().setRequestContent(holder.xml)

which will change:

   <soapenv:Header>
      <ns:RequestHeader>
        <ns:CompanyCode>xxx</ns:CompanyCode>
         <ns:UserName>xxx</ns:UserName>
         <ns:Password>xxx</ns:Password>
         <ns:DataStoreName>xxx</ns:DataStoreName>
         <ns:RequestId>xxx</ns:RequestId>
      </ns:RequestHeader>
   </soapenv:Header>

to:

<soapenv:Header>
     ${=context.testCase.testSuite.project.testSuites["TestSuite-Project"].getTestCaseByName("ConnectionProperties").getTestStepByName("DataGen").getPropertyValue("RequestHeader")}
</soapenv:Header>