your data base should be using linking tables, which you are not using
for example, you need a table to define zones:
then a table that defines the counties that belong in a zone:
and include a record for each country to assign it to a zone by the zone ID
then in the shipping cost table, bind the cost to the zone using the zone ID in the ShippingCostZone column
you can then use a joined query to join all the related tables together.
This sort of database setup and SQL Goes beyond what we can help you with in this forum, I suggest signing up for a premiere appointment so we can work with you on this.