....

Instead of using

on *:TEXT:!staffme:#: {
  if ($nick isop $chan) {

You can set the channel to a variable and make it to only pick up on the command IN that channel. Let me break down my code for you.

;When you load the script it will run this..
on *:load: {
;setting the channel set for the staff only
 set %StaffChan $$?="What is the staff channel?"
;setting the channel the StaffChan is set to look for ops in
 set %UserChan $$?="What is the user channel?"
}
;This uses %UserChan because that would be the channel you want the ops to be able to ;get access to your staffchan
on *:text:!StaffMe:%UserChan: {
;checking if the user has op in %UserChan, if they do it will invite them to %StaffChan
 if ($nick isop #) { invite $nick %StaffChan | notice $nick Invite sent. }
;But if they aren't
  else {
   notice $nick Denied. You aren't op in %UserChan $+ .
   msg %StaffChan $nick tried to get in.
;It will deny them, and notify %StaffChan that they tried to get in.
  }
}