Oh yeah I forgot about Mu, I don't have her either.
I thought the 'balance patch' is free, and Plat costs money.
Either way, you just add a user to your PS3, and during set up, just select that you live in Japan, make a bogus adress and select city and all that, etc.
If it does cost money, I have some in JP accounts wallet, that was left over from Arcana Heart DLC colors, if that's enough for the balance patch, I'll get it.. if not.. I guess I'll get another card and just get the chars.
Or just skip CS2 completely. Depends on how I feel.