Ask for a Domian and user name?

Looking for a way , that after a machine is imaged,when the machine boots up, it ask for a Username and Domain. NOT at the logon screen. I would like to join the User and Computer to the domain after the machine is imaged.
Second
I have created a Dos boot disk that logs the computers on to the domain for imaging. and would like to know how to set the diskette up that would automactically enter the user name and password, and just keep running, at the present state I have to press enter at the username nad then Type in the password. Would like to bypass this.