Weird kind of question: to do with horsy people! =)?

I'm a competitive horse rider and I'm really good at it. i want to compete in the Ekka showjumping competition for horse riding but i don't know how to register. does anyone know anything about registing for a competition at the Ekka? We're looking so far at 2012/2013/2014/2015 Ekka showjumping comps. If no info on Ekka, please feel free to name any other horse riding competition (preferably jumping) events around Brisbane. Thanks! =)