Help with shipping zones please!

Hi all - I operate a UK based store.

I am using the zonetable weight based shipping module.

I have two zones defined - UK and Europe with different shipping rates for each.

The problem I have is that some zones within the UK (Highlands of Scotland and Northern Ireland) carry an additional courier surcharge.

Any ideas please of how I could compensate for this in Zen? At the moment if a customer is in Northern Ireland it just charges them the standard UK shipping.

Many thanks in advance.

Just to clarify my post above, basically I need to have Northern Ireland and certain postcodes in scotland classified as part of my European shipping zone rather than my UK shipping zone.

Just in case anyone else is having the same problem I may have found a solution here : http://www.zen-cart.com/forum/showthread.php?t=97399

:)