I don't fully understand your work flow, but I do something similar, so I know it can be done.
I don't know if your ID is your key field (hope it's not).
I import the records to separate table. Do a find for blank lines/records, and delete found set. This leaves you with the usable records.
What happens next I guess would depend on how you append your project ID. For example, for Project 4, today you append records (4.1, 4.1.1 respectively).
What happens tomorrow when you append project 4? 184.108.40.206 or 4.2