I would like to create a small Excel app that would do the following:

Let the user log in (entitlements would be stored in a hidden sheet)

Question: how to create an Excel workbook that upon being opened would
present the user with the login form, and hide all other spreadsheets, as well as any menu items in standard Excel to make sure that the user can not access the hidden spreadsheets or other Excel features ?

Thank you,
Vlad