i have some moderators and i don't want they to have an admin cp acess but i want to give them premission to bann members :( i would like if there will be a bann opition in the warn panel

You can allow them to suspend an account.

i know but i need full ban

Well considering your forum has 28 members, I'm sure you can have them suspend the account and then you ban them later on ;)

But this IS a good idea.

ok, but i suggest that to other forums too

I agree here too, only admins can move members to the banned group.

i have some moderators and i don't want they to have an admin cp acess but i want to give them premission to bann members :( i would like if there will be a bann opition in the warn panel

I don't think any administrator would trust a moderator banning members. Moderators can have the power to suspend members from a specific forum, but I think the Ban the Member power is for global moderators and administrators only :).