yes, correct zip-code for Preding. in german zip- code is Postleitzahl (PLZ).
at community-site Preding you can see it:
http://www.gemeinde-preding.at/kontakt.html
http://www.herold.at/telefonbuch/albin-rucker/

on a letter you write correct in this way:
Albin Rucker
Tobis 23
8504 Preding
Steiermark
AUSTRIA

or
Albin Rucker
Tobis 23
A - 8504 Preding
EUROPA

Tobis is a community/hamlet belonging to Preding - map for his adress:
http://maps.google.at/maps?hl=de&bav=on.2,or.r_gc.r_pw.r...

the austrian zip codes/Postleitzahlen - left side the states then you can take in a list A-Z the town you need:
http://at.postleitzahl.org/
example > zip code Preding: http://at.postleitzahl.org/steiermark/preding/