Hi Cecilia
Good for you for keeping the ArchiCAD spirit alive in your country!
Unfortunately our friends at Graphisoft have been promising us registered examiner certification for some time now (
http://www.graphisoft.com/community/certification/rules/), but have never come up with the goods.
Maybe we'll see some alternative certification pop up in the near future. I also think GS may be more than a little shy to put their stamp on anything that is not either produced by them or closely monitored by them for legal reasons. I can only assume that is why there is no (creditable) official GS authorized certification.
Good luck to you.
Cheers,
Link.