Christ is the high priest in the old sense, and the only one. Christian priests are just ministers of Christ. We believer they received their authority from the Apostles through the successors of the apostles, the chief priests whom we call bishops. The power to ordain came from the Apostles, who selected priests and deacons and passed on the ordination power to some of them, called bishops. Now this is the schematic. How it worked out historically is hard to see because of the scarcity of sources, and the writers of the New Testament, as in so many cases, do not bother with such details. We do know that by the time of Ignatius that that was the way he saw things and we assume it was the norm.
Go get the book "Biblical Eldership" by Strauch ... if you muster up the courage to read it ... you will understand why the RCC ecclesiology is unbiblical.