[mamorunl]

You can deny access to the server for a period of time. Like checking if the player's name or IP is in a certain file. You then kick him as long as the name is in the file. If the time is up, let a timer remove the name/IP from the file.

or set a timer that will initiate the rcon command 'unban ip' and 'reloadbans'. Which is also an option