Wonderful! The next steps in Ray's previous comments states that we should:
Store that returned rate as a session variable and add a shipping charge rule to the cart to charge a flat rate of the value of that session variable.
I'm not sure if I have created a session variable correctly, however, this is what I have done: From the bindings tab + session variable, named it "deliveryFee", click OK.
If I have done this correctly, how and where do I apply the rule that will apply the delivery fee (for the appropriate city) to the confirm page and final total of the cart?