Hey im brand new and pretty terrible with my mac.

I got my powerbook aluminum in japan like 6 years ago, and hadn't really used it since i moved away. I have an airport extreme card in it, and its Locale is Japan. I got it connected wirelessly to my router here in australia by changing the wlan settings on the router to use channel 12 istead of 1. (japan uses 11-14, australia 1-14)
Im not always going to be able to change these setting on the networks i use, so im wondering if theres a firmware update that will allow my airport card to use all channels? or do I need to get a new card?>

ok thanks for any info