Hello,
As having 8+ years of experience with PostgreSQL, I would be able to do this task.
As I understand, The data is in csv file, which needs to be matched with rows in a table and again needs to be inserted in same or another table. It can be done via a script easily. I have some other suggestion as well to do this task like by loading csv in a table.
Once I understand what you exactly mean by create new records, the solution can be finalized.
Regards,
Hima.