Billing guidelines for NP



I work for a surgeon & we have a new NP who we are in the process of getting credentialed. I know that until that happens, the NP can see patients when my doctor is in the office & we can bill under the doctor's provider numbers. Is there any other way for this NP to be seeing patients on days when my doc is not in the office? Can another credentialed NP supervise?
Also, my practice manager (who is not a certified coder)is telling me that we can cover ourselves by just putting the patients on the doctor's schedule (even though he is not in the office)& then letting the un-credentialed NP see the patient & bill the claim under the doctor's provider numbers. I feel like this is false billing. Can anyone please advise?