Copying lots of data into a calculator and listing results back with original data

Morning all,
I have a spreadsheet calculator that is unfortunately protected that returns a number when a postcode is entered.
I also have a huge list of postcodes that I need to run through this calculator and record the numbers returned.

Any ideas how best to copy the postcodes across to the calculator and then copy the resulting number back to my postcode list in one go? If not i may lose the will to carry on with the next 5000 postcodes!

thanks in advance for any help offered.