In Microsoft Excel version 4.0, all you need to do to convert a macro to an add-in macro is save the macro sheet in the add-in file format; after you do this, the macro sheet will be hidden from view. Microsoft Excel 4.0 add-in macros still run in Microsoft Excel version 7.0. (Add-in macros are called add-in applications in Microsoft Excel version 7.0.)
To create an add-in application in Microsoft Excel version 7.0, you use the Make Add-In command (Tools menu) while a Visual Basic module, Microsoft Excel 4.0 macro sheet, or dialog sheet is active. However, before you convert a workbook containing Visual Basic code to an add-in application, you must save your code in a workbook with a different filename if you want to continue working with the code. After you've converted a workbook to an add-in application, you cannot edit code in that workbook again. You can distribute your add-in application to other users of Microsoft Excel version 7.0, who can run your add-in application but cannot see or change your code.
For more information about add-in applications in Microsoft Excel version 7.0, see Chapter 11, "Automatic Procedures and OnEvent Procedures."