Port number for programmatic invocation of WebFaced app

I am trying to use a RequestDispatcher.forward() to invoke a WebFaced
application as described in the help topic "Integrating WebFacing
applications with other Web applications". The forward code I used is:

// Forward to webfacing
getServletConfig().getServletContext().getRequestDispatcher("WFInvocatio
n.do?inv=" + invocation + "&userid=" + user + "&password=" +
password).forward(request,response);

When I run this code I get a error page with error "WF0103: An error
occurred while establishing connection with the WebFacing server on the
host." Under additional information is another error "WF0055: The
specified port &1 is not a valid number."

I am not sure where the port number is supposed to be specified. Can
anyone help me resolve this problem?