https://blog.maartenballiauw.be/post/2008/03/Reuse-Excel-business-logic-with-PHPExcel.html
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Embedding business logic in Excel and re-using it in PHP is not that hard. The PHPExcel library helps you simplify development: your application logic and business logic is separated. Business logic can be maintained by a business expert or key user in Excel. As an application developer, you can easily pass data in the sheet and make use of PHPExcel's calculation engine.
