/u/Dpwman_2165 has previously answered Did Mussolini or other high ranking Fascist Party members consider abolishing the papacy instead of granting them Vatican City in 1929?, which is the closest to your question.

/u/Domini_canes has also written in a thread titled Hitler's Pope, Catholicism, Nazism, and Fascism, which talks about the relationship between Catholicism and fascism.

EDIT: Note also there are dozens of books about church & state in Fascist Italy, to give you an idea of how complex this question can be.