I use an auto numbering algorithm to assign client ID # to each new client.
I need to convert my existing client database into Airtable with the existing ID # but need all new entries to use an auto assignment. (I see that Airtable will not allow me to enter the ID number in the field if I have it formulated to auto-number, so I cannot override it). So, how do I convert my existing records and then auto number within the same field?

Also, my current ID schema is “0660” followed by the 2-digit year followed by a 2 digit auto number. For example, the last client I signed in 2019 (using previous database application) was 06601953. I need my first client for this year to be 06602001 and all remaining this year to be 02, 03 and so on. What is the formula for that?