Feyen/Trier

Hi,
    I was wondering if someone could help me please. My father was born in Pirmasens in Germany. I have a confirmation certificate saying he lived in Caserne de Castelnan in Feyen.
Decanatus TREVEY-TRIER
Cura Animarum TREVEY- FEYEN
Ecclesiae TREVEY-FEYEN

Feyen and Trier are both places quite close to Pirmasens. I had heaps of trouble with the Trevey but have since been told that that was the old name for Trier? I have written a letter in German to send to them but have no idea how I would find the correct church to send it to. Could someone please tell me how I go about finding it? The reason is the certificate has a few discrepancies like he was only 2 when he was confirmed. I have some photos taken at what looks like his confirmation but he is at least 8-10 years old. Could this be common practice and I have made a mistake? as I am Roman Catholic I do not know much of the Greek Church. I am also after my grandfathers death certificate which has to be either held in the church that services Trier/Feyen or Pirmasens. The Church is the Graeco-Catholica Ecclesiae in Germania. Any help would be immensely appreciative. Thanks for your time. Samantha