Cross domain web service access.

I am writting a program in vb to access a few published web services that are in a different domain. As long as I am in the same domain I do not have a problem adding a web reference. It would make my life easier if I can add it in my domain ( the parent). This is the error I am recieving. Any help is appreciated.

There was an error downloading ‘http://webserviceserver:7047/DynamicsNAV/WS/services’.
The request failed with the error message:

<s:Envelope xmlns:s=""><s:Body><s:Fault><faultcode xmlns:a=“urn:microsoft-dynamics-schemas/error”>a:Microsoft.Dynamics.Nav.Type