I would advise you to extract the postcode from column A on sheet 1. Not sure how the address is structured, but if the postcode is last, you could use the Right function:
Or using the 'Text to columns' option found under the Data ribbon, depeding on your format.
Once you have done that, you can use VLOOKUP.
Make a habbit out of placing each type of data (street, number, city, postcode) in a separate cell to make data processing a lot more convenient. It also creates a better overview.