shipping by weight, but free to some areas

Hi

I have successfully set shipping to use weight (table).

The problem is, free shipping applies to certain post codes within local area.

Can anyone suggest a way i can run free shipping as well as table rate (by weight), so, if customer lives in local area (local postcode) the system notices and applies free shipping?

I have made some progress...

I have set up an area called North Devon under Zone Definitions

Have also set up a zone United Kindom > North Devon under zones

I am aware that if this works i will have to set all counties in UK, which will be a pain, have to do this so all counites come up under States and customers can choose state when checking out - if they choose north devon, then bingo, the system should apply free shipping

consequently, i have set free shipping to only be applicable to north devon

ok, done all that, but...

when i choose north devon from drop down, or type North Devon into text field free shipping isn't applied

any help or ideas would be very much appreciated