This what You are asking for should be written in the external amx/amxx plugin. This functionality is unique and none of bot coders would put into bots code. If You are using AMXMODX - here is the right place to ask Your request:
http://forums.alliedmods.net/forumdisplay.php?f=12
But first You have to decide what bot You want to use on Your server - then ask AMX X coders to write the plugin for this exactly bot (each bot has its-own commands, so the plugin coder has to know what commands he can use to add/kick bots).