OK, what is the best way to do this ?

I am shipping to the US only and I need to divide the country into 8 zones per DHL's rates. Each zone needs to be defined (I suppose by state or zip) and then each zone must have a rate table by weight.

This would seem like an obvious thing to do yet nothing I have seen yet indicates the right way to do it.

So far I have only setup zencarts for the UK or Europe and in that case the regular zone shipping module works fine because you create zones by country but I see no such equivalent to create zones by state or zipcode range etc. (version 1.3.7)

Thanks,
Trillian