I'm using Zen Cart 1.3.8a and trying to figure out if there is any way to set up shipping zones with a greater degree of precision than just using country codes. Right now I have set up a shipping zone for Canada and for the US, but realistically the cost to ship is quite different for someone in Ontario (as we're in Toronto) versus someone in Vancouver.

I've seen that there's a third-party module that does this, but is it at all possible using the stock shipping modules? Being somewhat of a layman as far as these web things goes I fear I may just mix up a third-party installation so want to avoid that unless there's no other option...