Looking for help trying to find a way to add an editable

Looking for help trying to find a way to add an editable XML type spreadsheet to a clients website.

I found a wordpress plugin called dxhtml or something similar, but it doesn't allow formula's to be added and kind of misses a lot of features. Not to mention, the plugin hasn't been updated in 2 years.

Client is trying to track daily sales, devices sold, accessories sold, etc. Currently they use a Windows server and allow their store locations to VPN into the computer to edit their specific spreadsheet for the store. Trying to simplify this.

Thanks for the help!