CRM Link to Zoho CRM for Internal Extensions

Calls from internal extensions (eg 101) opens the CRM record in Zoho CRM but matches the first contact found with a phone number matching the extension (eg 101 as the caller id would match something like 0712345*101*).

We would like to prevent the CRM popup from opening for internal calls.  Can a pattern be used somewhere to prevent internal extensions using the crm module? eg if the caller id is 3 characters in length, ignore it.