Hi Jonkka, how are you? I checked in some old results, and Dani Sordo's codriver was Juan Antonio Castillo Ferna, whereas the current driver is Juan Antonio Castillo Fernández, so I think they are different people.
Edit: on second thoughts, probably Ferna should be Fernandez, but it just didn't fit in the table, so now I do think he is the same person...
And then I had the presence of mind to just look it up in the old Rallybase database tables I still have, and I had him as Juan Antonio Castillo Fernández all along in 2003. So it is very likely he is the same person currently driving a Rally2 Ford Fiesta.