What do you mean "all spreadsheets that I open"?
Do you really mean "all workbooks that I open"?
If so, record or compose the macro and stick it in your personal macro workbook, which will run on the workbooks on your computer.
If you need the macro to run in workbooks that would be opened on someone else's computer, or if you really did mean spreadsheets instead of workbooks, then you need a different answer, so repost with those details if that's the case.