The best you can do, if I understand correctly, is to have the event triggered each time, and have the conditions checked, and if none of the conditions fit, then do nothing.
With the speed of most computers these days, you'd probably need a 250+ line code before anyone might notice that a script was/was not responding.
Basic code:
on *:text:*:#:{
if ($1- == first condition) {
;response for first condition
}
elseif ($1- == second condition) {
;response for second condition
}
elseif ($1- == third condition) {
;response for third condition
}
elseif ($1- == fourth condition) {
;response for fourth condition
}
elseif ($1- == fifth condition) {
;response for fifth condition
}
}
I only did 5 sample conditions, but there's (realistically) no limit as to the number of conditions you can have.