Panasonic KX-TD1232NE Programming Manual page 87

Conditions
Example:
If the removed digits are assigned as "6" and the added number is assigned as "2," the number
sent from the network is changed as follows:
85492603 (DDI number: 2 digits)
Six digits are deleted and "2" is added, and the number becomes "203."
Feature References
Direct Dialling In (DDI)
General Programming
2.2 System Programming
87