Nintendo wi-fi Help

Hi everyone, I can't connect my ds to the internet because I have BT infinity which uses WPA2 Security and I was wondering if there are any way of me connecting to the internet without changing my security setting or buying one of them stupid nintendo dongles.

I have read however that you can connect another router to the internet which can have WEP settings and still have the other router on with WPA2 security however i do not fully understand this and I was wondering if anyone can explain it me in nice simple steps and if this way does work could i use the bt homehub 1.0 router

thanks daniel