Do I have to be on a car loan to be on the registration?

Last June, I tried to finance a Honda Accord but I needed a co-signer, my boyfriend cosigned for me, but the dealership said they found a better loan rate without me on the loan. So for the past year I have been paying for the loan & insurance, totaling about $8311.44 as of today. On Friday the 13th, my boyfriend(ex)now took off with the car that he has not paid 1 cent on & said he isn't bringing it back. I just want to know how I can be added to the registration?