To do this, we have added a lookup field called Parent Account in the contact form. This Parent Account is a lookup field that shows the account when clicked on it.  

Now in the accounts form, we have added a lookup field called Territories. Of course it lists the crm territories.

Those 2 lookup fields (Parent account and territories) are both mandatory fields.

Now I have accounts and contacts to import and I just can't find the way to populate these fields because they are just not there in the list of available fields for each of the entities...  Tell me there's a workaround... please !...

Thanks