SoapUI API for Authentication

Hi all,
Have a scenario to authenticate(passing: Domain, Username, Password) secured wsdl through API than the SoapUI tool. Getting "Unauthorized error" for below code.

WsdlProject SoapUIProject = new WsdlProject();
WsdlInterface SoapUIInterface = WsdlInterfaceFactory.importWsdl(SoapUIProject, null, true)[0];
WsdlOperation SoapUIOperation = (WsdlOperation) SoapUIInterface.getOperationByName(strWebMethodName);
WsdlRequest SoapUIRequest = SoapUIOperation.addNewRequest("Myrequest");
SoapUIRequest.setRequestContent(SoapUIOperation.createRequest(true));
if (strArguments.length() > 0) {
String strRequestXML = SoapUIRequest.getRequestContent();
String[] strArgs = strArguments.split(",");
for (int i = 0; i < strArgs.length; i++) {
String[] strArg = strArgs.split("=");
strRequestXML = strRequestXML.replace(strArg[0] + ">?",strArg[0] + ">" + strArg[1]);
}
SoapUIRequest.setRequestContent(strRequestXML);
}
WsdlSubmit SoapUISubmit = (WsdlSubmit) SoapUIRequest.submit(new WsdlSubmitContext(SoapUIRequest), false);

Please suggest me to resolve this issue.
Thanks in advance.

Regards,
Vijay D