iBook G3 WEP airport vs airport extreme WPA2 protocols?

Hi all,

I've recently discovered a deep love for my old iBook G3 that I adored and asked the impossible of in uni. I really want to get this old dinosaur on the network, so I sourced a 2nd hand airport card and am trying to connect to the network broadcast by my airport extreme. Problem is, it uses WPA2 and my AirPort control panel on the old G3 running 10.4.6 wants WEP. I'm not a complete n00b, but I'm not as techincal as some and I'd welcome your advice for getting this G3 on the WPA2 network. Any thoughts??