Let say I do not want my users to call any oversea numbers. How can I drop those calls using a routing rule? We need to dial using the format 0011<CountryCode><number> .
I can match the 0011 but don't know how many digits the full number is. Which mean I can't discard x (unknown number of) characters and then prefix with a predefined extention with a voicemail msg to say you can't call those numbers.
Currently I just add the string BLOCK in front of the number so it becomes "BLOCK0011<rest of the number dialed>, which means the call will fail and not get through.
Is there a better way to do this? How do I discard the whole number (of unknown length) being dialed and prefix with another number or extensions etc.