§1. In every diocese, after having heard the college of consultors and the Finance council, the bishop is to appoint a Finance officer who is truly expert in Financial affairs and absolutely distinguished for honesty.
§2. The Finance officer is to be appointed for a Five year term but can be appointed for other Five year terms at the end of this period. The finance officer is not to be removed while in this function except for a grave cause to be assessed by the bishop after he has heard the college of consultors and the Finance council.
§3. It is for the Finance officer to administer the goods of the diocese under the authority of the bishop in accord with the budget determined by the Finance council and, from the income of the diocese, to meet expenses which the bishop or others designated by him have legitimately authorized.
§4. At the end of the year, the Finance officer must render an account of receipts and expenditures to the Finance council.
Source: Code of Canon Law (Vatican.va)