Brendan:
The Church does not have the authority to do so. All the Sacraments were instituted by Christ, the Church is simply the caretaker of what Christ, through the Apostles, have given to us.
The Church cannot add, nor subtract from that.
I am a priest (presbyter). I cannot administer Confirmation because that is a sacrament reserved to the bishop.
However, despite that, there are times when I can be given the faculties to Confirm.
Would we not say that is an example of the OPs question?
I am not too sure that it does. My take on the OP was creating a new degree of Holy Orders, more than Diaconal but less than Sacerdotal.
In other words, a man whose ordination allows him to Anoint and Absolve, but lacks the Sacramental authority to confect the Eucharist, not simply a lack of faculties.
You can Confirm because the authority to do so is inate to Sacredotal oders, you simply lack the faculties to do so normatively.
If I understand the OP correctly, they are asking if the Church could establish a new degree of Holy Orders ( I’ll call it ‘UltraDeacon’) that can be granted faculties to Anoint and Absolve, but lacks Sacerdotal Orders.
Currently no bishop, not even the Pope, could grant a Deacon faculties to hear Confessions. The man in question would have to be Ordained to Sacerdotal Orders. But an ‘UtlraDeacon’ could be granted such faculties, but could not, even by the Pope, be granted faculties to say Mass. Again, the person would have to be Ordained to Sacerdotal Orders before such faculties could be granted.
Such a new degree of Holy Orders, in my understanding, would be outside the Authority of the Church
I could be mistaken in my understanding of the OP’s request though.
You may be correct that they are asking for a person in Sacerdotal Orders, but is simply denied faculties to say Mass.