Logging into a SQL from other domain

Does anyone know how to configure the log in process to SQL 7, when using NT authentication, to allow a user to use an id from an NT domain other than the one their work station is logged into?

Example: When I log into my machine I login to domain A with id user1. However I have an id that is in domain B that is user2. The SQL permissions are set such that user2 from domain B has permissions. However when logging in using NT authentication it does not let me try and put in another id such as B\user2. Any thoughts on how to do it?