Monetizing Excel Spreadsheet

Question

To Whom It May Concern,

I have entered conditional formatting into an Excel Spreadsheet that I use for scoring a psychological assessment. I would like to monetize this by giving customers brief access to the document, but not allow them to see any of the "code" I used. Basically, when a person enters data on a table in an Excel spreadsheet, highlighted cells appear in a corresponding grid in the same workbook. I'm looking to give them access to the document on piecemeal basis for a flat rate. Any suggestions?

Thank you!