Connecting to wireless on a macbook before 1st login

Hey everyone,

I am trying to figure out a way to boot up a macbook and click on the wifi icon in the menu bar to enter credentials, before a users first login.

Right now I can't see a way to do it, hovering over the icon with the cursor doesn't do anything.

I have to prep about 400 of these for a school I work at, and have to figure out a way to athenticate a user for first login, but it has to have an internet connection to do that.

I need the user to be able to just turn it on, whether at home or work and join a wireless network before attempting to log in.

Any ideas or am I missing something here?

Thanks again