Ok, that makes sense, that the bot doesn't want to be flooded off the server

I already thought about it to make a script, which builds its own queue and notifies every user, that he is on hold (may be with the queue number). This way, the user doesn't make any more requests, because he thinks the bot died (this would build up the bot-queue pretty good).
Is it possible to hold the process of one script as soon as a new requests comes in, adds the new request to the queue and returns to the other script? Otherwise i need a 2nd bot to do this, because of the process queue of the bot.