When i kick some one on a non-dedicated server he just joins
again how do i ban himbut for a limmited time?

I think you can just do:

Ban "PlayerName"

i find it easier just to get HLSW and do server commands from there.

It lets you kick or ban people for set ammounts of time

1minute 30minutes 1hr 1 day perm. And so on.

do status, then find the # infornt of his name. once you have that do banid (time in min) # kick. if you choose 0 it will be forever