The Code of Canon Law says:-
Canon 228: Lay people who are found to be suitable are capable of being admitted by the sacred Pastors to those ecclesiastical offices and functions which, in accordance with the provisions of law, they can discharge.
Lay people who are outstanding in the requisite knowledge, prudence and integrity, are capable of being experts or advisors, even in councils in accordance with the law, in order to provide assistance to the Pastors of the Church
(The obligations & rights of the lay members of Christ's faithful)
Canon 519: The parish priest is the proper pastor of the parish entrusted to him. He exercises the pastoral care of the community entrusted to him under the authority of the diocesan Bishop, whose ministry of Christ he is called to share, so that for this community he may carry out the offices of teaching, sanctifying and ruling with the cooperation of other priests or deacons and with the assistance of lay members of Christ's faithful, in accordance with the law
Canon 536: If, after consulting the council of priests, the diocesan Bishop considers is opportune, a pastoral council is to be established in each parish. In this council, which is presided over by the parish priest, Christ's faithful, together with those who by virtue of their office are engaged in pastoral care in the parish , give their help in fostering pastoral action.
The pastoral council has only a consultative vote, and is regulated by the norms laid down by the diocesan Bishop
(Parishes, Parish Priests and Assistant Priests)
In this Diocese the provisions of Canon 536 have not, as yet, been implemented. So for the time being we have constituted the 'Parish Finance & General Purposes Committee}