A new convert to the Catholic Church from the Anglican Church has requested to have an Anglican ceremony at our Catholic church by our priest to his Catholic fiancée. Is this valid?
As you describe it, that is a wedding ceremony that wouldn’t take place. First, Catholic priests do not preside over Anglican wedding ceremonies. In addition, it seems odd that a new Catholic convert from Anglicanism would want to marry his Catholic fiancée in an Anglican ceremony but at a Catholic church. Are you sure you have the facts of this prospective wedding correct?
A Catholic could marry a non-Catholic in a non-Catholic wedding ceremony at a non-Catholic church, provided they get a dispensation (i.e., special permission) from their local diocesan bishop (see Code of Canon Law, can. 1078; CCC 1635). And a Catholic priest could serve as a witness at such a wedding, although the non-Catholic minister would receive the couple’s vows in such a non-Catholic wedding ceremony (Directory for the Application of Principles and Norms on Ecumenism, 157). Yet with the permission of his local bishop, and if invited to do so, a Catholic priest or deacon could participate in the ceremony in some other way, e.g., reading from Scripture (Ibid.).
Further, even when a Catholic marries a non-Catholic, it would be highly unusual for a Catholic diocesan bishop to allow for an Anglican wedding ceremony to take place at a Catholic church. Again, such would normally take place at an Anglican/Episcopalian church, not a Catholic church.
Perhaps the Anglican convert to Catholicism is receiving static from some of his family and friends who remain Anglican. Perhaps they’ve said they will only go into a Catholic church for the prospective wedding if it’s an Anglican service.
But that’s not the way the Church will rectify this matter. It’s possible that a diocesan bishop might give a dispensation for a simple Catholic wedding ceremony, i.e., without a Mass, by a Catholic priest at a non-religious venue, such as the lovely atrium of a nearby hotel. I saw that permitted when a friend married an Orthodox (or Conservative) Jewish convert to Catholicism whose Jewish parents didn’t want to participate in a Catholic ceremony in a Catholic church. So, for pastoral reasons, the bishop gave a dispensation to have a simple Catholic wedding ceremony in the atrium of the local hotel.
Please check the facts of the prospective wedding you described again, and, if you’re indeed correct, see if my proposed solution—or something similar—might be worked out at the diocesan level.