Thank you for your query at DoctorSpring.com
I understand your concern.
While Novolog is an insulin substitute, Victoza is liraglutide, completely different from insulin. It acts in a different mechanism. And seeing his levels he needs insulin, liragutide won't be effective. Since both the products are different no exchage rate is possible.
I will advise you to take him to your local physician, and get the prescription for insulin, Also with sugar levels of 320 it will be prudent to get his urine ketone and sugar levels checked.
Feel free to ask further queries,