This is not a supported feature so it is not something that I will be able to offer detailed instructions for but here is an overview.
First create the table and populate it with the zip codes.
Next add a recordset to your confirm page, it will select all from this zip code table, you will need to filter it on the posted shipping zip code from the checkout page.
You could then set a session variable to the 2 day ground value for the shipping quote, you will want to make sure that the trigger for this set session variable is 'if the recordset was not empty', if it is empty then you would want to set this session variable to your other shipping option.
Finally you would update the shipping quote server behavior to make use of this session variable for the service type.
