Firstly you would need to collate the various international postal code
Once you have these you can continue to write VBA code and use IF to verify
the country and postal code format. Add a comment in another column.
Lets say for this example you have "Canada" entered in cell "A1" and the
exmaple postal code of "A1A 2B2" in cell "B1" in your spreadsheet.
Open the Visual Basic for Applications Editor (Alt-F11) and enter/copy the
Dim CountryRegion As String
Dim PostalCode As String
'Assign Spreadsheet reference
CountryRegion = Range("A1")
PostalCode = Range("B1")
'Use if function to check postal code is correct
If CountryRegion = "Canada" And PostalCode Like "[A-Z][0-9][A-Z]
Range("C1") = "OK"
Range("C1") = "Error"
All you would have to do know is use a loop to process through all your
records/rows of data. I hope this helps, and if you want more information
on Postal Codes and Macros then visit the MSDN web address below;