There are 2 clubs "near" by. First the MORAC in Graz with a pretty big onroad track, see:
www.morac-graz.at
And another track directly in Hartberg, see:
www.puchas-modellbau.com
The homepage is pretty out of date so you should drop them a mail.
The austrian association for rc cars (like brca) is the ÖFMAV - (I know that you have no Ä
) so heres the direct link;
http://www.oefmav.at/index.php?page=vereine&BL=Stei
There you can find all tracks and clubs in the southern area of austria. If you klick on a another state ou see more clubs and tracks but they are further away of course.