Hypothetically, at the end of your accounting course you could submit an application informing JPA that you wish to take post grad studies. You would need to produce some application info for the post grad course and the offer letter. Then they might approve your application.

A big part of the reason this is possible, is that there are so many people applying for jobs in the govt service. Easy job, maybe. Glamour, no. But that doesn't stop many people from applying. The supply is so high, I don't think they will be reluctant to let you go.