I have experience in this area as I frequently save documents as PDF to prevent editing by other people and then change it back to excel for me to work with.
Respected Sir,
I am looking forward to work with you. I am a hard worker and if you gave me chance i'll do my level best to get my job done on time. So that you don't have any complain with me or regarding my work.
Waiting for your positive reply.
Regards.