If I understand correctly, the excel file was used purely as an initial upload and you want to adjust those values weekly afterwards, but it is important that you keep track of those changes. Would you like to see how often an adjustment has been made and what kind of adjustments these were?

This sounds like a typical case of Audit Trail, luckily a module is available for this in the Marketplace. The Audit Trail module creates a log history for the changes made to objects in your Mendix application. This module keeps keep track of what changes are made in your Mendix application as well as when, by whom, and how much

https://marketplace.mendix.com/link/component/138
https://docs.mendix.com/appstore/modules/audit-trail