My Zen cart version is 1.3.8

Had 3 zones defined by the person who installed it as 1) USA, 2) Canada and 3) Others.

There is a different flat rate for all the 3 zones and then $1 is added per item. Hence the choice of zoneflat rate formula.

Now when I had to delete some countries where the shipping was not possible, I simply deleted them from the Locations/taxes - countries section.

Now, I want to include a few countries out of them, like Australia, France, New Zealand, in the same zone as Canada. All I could think of was inserting Australia in the folder Canada, but nothing happened.

How do I go about doing it?