hi! I'm glad you like it ;-)
About offical exam of soroban, I don't know much about it. I've heard of them in books I have read: Kojima's book and Cumin-Hossenlopp's book. It seems clear something existed in the past in Japan. But now, something might still exists.
And worldwide, there is no abacus association. And no exam.
But locally, abacus/soroban associations might propose such exam.
You could ask in the yahoo group for more details: http://groups.yahoo.com/group/SorobanAba... or check before the previous posts/messages.