PTA information

For the past 15 years I have been working as a physio/occupational/rehabilitation assitant in a acute care hospital. I was on the job trained with a full scope licensed practical nursing license.We are in charge of teaching and training the students of these three courses. My question is although I am what they call grandfathered in nowadays they want anyone new coming in to have a diploma. Is there anyway for me to challenge these courses or get them without going back to school for ever. Any info or advice would be great. Thanks Terri