How to block extensions so they cannot enter the queue number?

Hello friends! I really need your help… I’ve read 100 articles on the internet but I didn’t find the solution that I consider simple. Come on!

I have 3 service queues and I have 20 extensions in my switch.
I want to block internal calls or extension transfers to these queues when the queue number is entered.
Is it possible to do that?

As an example to block connections between extensions I used the following command in “extensions_custom.conf”:

exten = _1XX/_9XX,1,Hangup()

With this code, the default extensions 100 do not communicate with the default extensions 900…

I want to do the same thing but with queue, so that an extension dialing the queue number the call is disconnected…

Is it possible to do that?