Acceptable dial plans by User Extention

How can I restirct a specific extension to allow outbound access only if that specific extension dials a specific pattern of numbers. And at the same time deny any other outbound access.

Vincent

Check PIN sets on Outbound Trunks. They require the user to key in a passcode before it’ll make the call.

That would be a global setting. I want it defined by extention with no password.

Could I modify:

sip.conf

[210]
context=xplan1

[211]
context=xplan2

extentions.conf

[xplan1]
dialplan1 dial patterns

[xplan2]
dialplan2 dial patterns