After defining your Pricing Points and Zones, and assigning a freight differential to each, you select the desired values for each Contract on the Contract window:

Notice that, if the Daily Market Price has also been set up with (at least) a Base Commodity and price, the current Daily Market Price for the selected Pricing Point and Zone is displayed on the Contract window. You can also define a per-contract Mark-to-Market adjustment value to be included in the reporting calculation if you wish, using the text box also available on the Contract window.