Well it seems l2walker OutOfGame will no work at the moment at L2Extreme servers.
If you wanna bot the only think you can do is to use InGame Botting.
To play on L2extreme using In-Game L2Walker, do this:
1. Go to

and download the IG version of L2Walker.
2. Download Xen's VerifyServer Emulator

and extract it to the folder you have your IG L2Walker on. You also have to modify your hosts file, found on:
CODEc:\WINDOWS\System32\drivers	 2;etc
and add these lines:
CODE127.0.0.1 vip.towalker.com
127.0.0.1 vip1.towalker.com
127.0.0.1 vip2.towalker.com
127.0.0.1 vip3.towalker.com
127.0.0.1 vip4.towalker.com
127.0.0.1 vip5.towalker.com
127.0.0.1 vip6.towalker.com
127.0.0.1 vip7.towalker.com
And save the changes.
3. Run Xen's VerifyServer Emulator, and then click Start.
4. Run IG L2Walker.
5. You can configure your walker by pressing home key in game. (Inicio in spanish keyboards)
6. Enjoy your botting.