To use it, click on the above link,
choose the "save this file to disk" option,
open the Excel spreadsheet on your local machine,
and edit the blue text in the Excel cells.
(Might help peace of mind to apply a virus checker first.)

Latitudes are degrees North and longitudes are degrees West.

I offer this "freeware" as-is with no guarantee of reliability,
and anyone is free to do with it as they please.

If anyone chooses to play with it (e.g., rewrite it in Java),
or discovers an error in it, I'd appreciate an e-mail.