Domain add on VS redirect

Hey folks,

If you re-directed a domain to a blogger blog for example, does the redirected domain still rank in Google? Or does the domain need to be an add-on domain like you use in host gator?

Sorry I think I worded that a little retarded but I'm fairly new to this still =)

Don't redirect it, but add it to Blogger, and then update your domain records with Blogger supplied information.