Create Zimbra Admin Extension to Add additional Field for Zimbra User account

I would like to add few more additional fields to Zimbra current user contact information. - Registration ID - Designation - Designation Code - Designation Status - Office Phone - Mobile Phone - Department Code - Department Name However, the functionality will not just limited to the above fields. any other fields can be added. All data will need to be save to Zimbra LDAP. Zimbra version 8.6