[exim] SmartHost with Exim

Hi, list!

I need to configure Exim to use an InternetProvider as SmartHost.
I think, I have just to create a new manualroute for all non-local domain and
give the IP/Name of the provider.
But how can I specify a UserName/Password for this Provider?

Thanks a lot!
Luca Bertoncello
(lucabert@???)