You can modify the outgoing profile for calls to use variable digits instead of a fixed amount of digits. If you open CCA and go to the Configure -> Telephony -> Dial Plan -> Outgoing section. Look at the dial plan with the "National" permission. You can change the number of digits to "variable" in the "Number of Digits" column, this way it will send whatever you input to the local telco without requiring the full 10-digit number.