After becoming Auxiliary Bishop of Buenos Aires on 15 May 1928, Copello was named Vicar General of the same see and Vicar of the Argentine Military Ordinariate on the following June 12.
Nakon što je postao pomoćni biskup Buenos Airesa 15. svibnja 1928., Copello je imenovan generalnim vikarom iste biskupije i vikar argentinskog Vojnog ordinarijata 12. lipnja iste godine.