It needs Clippy-ing: "recognise column as zip codes? always, now, not now, never, turn off format recognition".
If the column is going to be called something stupid like A, B or C clippy is going to have a hard time....
Maybe, given the appropriate locale in the system settings.
Oh no, Jesus, please no. Nothing better then Excell file what behaves completely differently when moved to another computer, purely because of something like locale in system settings.
First, you should not conflate the locale of the user or program with the locale of the (span in the) file.
Second, how would you handle international addresses? For many businesses, a program that can't do that would be useless.