They will probably ask you in your interview what your goals are or "where you see yourself in 5 years" (or something along those lines), so I would go ahead and put the fact that you are an RN on your application. They also already have your information on file for when you applied to those RN positions.
And yes, not identifying yourself as an RN means when you are working. You just can't go around telling your patients that you are a nurse and partake in those nursing skills (med administration, IVs, etc).
As a PCNA, you will be doing a lot of very basic nursing care - bathing/hygiene, toileting, I/O, blood sugar checks, d/c foleys/IVs, vital signs and helping to answer call lights. I was also allowed to do very simple dressing changes. Look and see if The Clinic still offers a PCT (patient care tech) position. You will have the same duties as a PCNA but you can also insert foley catheters and draw blood.