Change webservice url without changing soap endpoint in IBM webservices?

Question

I'm using a webservice client generated using Rad 7.0 which is implemented using the classes in com.ibm.ws.webservices. I need to override the url which the soap request is sent to (for an internal proxy) but still have the soap endpoint entry be the true url, for validation.

How can I override the destination url without overriding the soap endpoint?

FileHostingServiceLocator fhs = new FileHostingServiceLocator();
FileHostingServiceSoap soap = fhs.getFileHostingServiceSoap(); 
ttResponse = soap.transmitData(webServiceUser, webServicePassword, customerInfo.getFileName(), image);