ext4 file system mounting on debian lenny.

[Mehran Parchebafieh <axon0098@gmail.com>]

I have a partition that it's file system is ext4, I want to have full access on it. How can i do that?!
my kernel version is 2.6.26-2-686 
Debian GNU/Linux 5.0.4 "Lenny"
ext4 kernel module exist but i can't mount it.
Thanks.