Come to give my contribution to customers who want us to care for the V3,
I made the Following:
1 First I created the fields in the entity clients
2 Then I used SqlCe40Toolbox to see the fields in the table entities
3 - In excel I divided the customizable fields in columns and acresentei separate data and another worksheet used a formula a1 & a2, and so on to join separated columns and saved in csv
After 4 SqlCe40Toolbox cared for, ready in 10 min imported 4 million customers with custom fields
If someone did not understand please report here, I hope to have contributed
