Most ircd's support userip command, So id go with that.
menu nicklist {
Akill:set %a_kill_reason $$?="Reason to akill?" | .enable #a_kill | .userip $$1
}
#a_kill off
raw 340:*:msg operserv akill add +7d *@ $+ $gettok($1-,2,64) %a_kill_reason
unset %a_kill_reason
.disable #a_kill
halt
#a_kill