as far as I know there isn’t a way to do this on the admin portal.
RC has a “do not call list” which is a bunch of blacklisted numbers RC considers to be high-risk/spam/scam destinations. And if you trust one of these numbers and want to call them you first have to get the RC Fraud department to whitelist them for your account.
The reason I am telling you this is because RC is able to block outgoing calls to specific numbers from their backend.
I suggest you try raising a case for this, provide RC with a list of numbers and ask RC to blacklist them for your account only. Then if one of your agents tries to call one of the blocked numbers they would hear something like:
“The destination you dialed is disabled for your account. To have it enabled contact your administrator”
Hope this works and good luck.
Thank you very much for the feedback, I’ll give that a shot.