I am fairly new at OB/GYN coding....Can you bill for 76817 in the office if the patient is inpatient?

Same date of service: Patient is inpatient and being taken over to the physician's office for ultrasound and the physician wants to charge, 99232 (POS 21) 76817 (POS 11).

I really don't think this can be done but I need to know where I can find regs. to prove this to them. Any suggestions or links to where I can find out if this can be done will be greatly appreciated!