How to Blacklist of numbers with Regex in a Menu?

[Tuly]

Based on this conversation on how to change caller ID when
calling out,
https://helpcenter.2600hz.com/2600hz/topics/caller-id-changer

 We are creating a call flow of lest say number 8>Dynamic CLID>Disa but I would like to make sure that no one can dial this call flow “8” from the outside by calling in the IVR, how would I restrict dialing 8 from an IVR with Regex in the advance options of a menu? (but still allow dialing 108)

[Logicwrath]

In advanced call flows, menu, advanced you can see this:

http://prntscr.com/clfct6

[FASTDEVICE]

This expression may work for you: 1\d{2}[^8]