Hi, Denis —
None, that I know of.
He can ask to make an appointment with the Bishop
or Cardinal to talk about the process of becoming
a priest but the ultimate choice is the Church's.
No celibate Catholic man has any right to be a priest.
The Church, after careful examination of the various
seminarians, chooses men for the priesthood.
To that extent Jesus Himself chooses each man to
enter into His ministerial priesthood.
Hope this answers your question.