What does HackerNews think of ImportExcel?
PowerShell module to import/export Excel spreadsheets, without Excel
Language:
PowerShell
> "Sometimes the feedback involves making a minor tweak on every Worksheet."
Could be a good task for PowerShell and the ImportExcel module[1].
(PowerShell also being a .NET language and written in C#; it has convenient access to COM control of Excel if you can't import the spreadsheet and export an updated version; through $xl = New-Object -ComObject Excel.Application )
The ImportExcel (https://github.com/dfinke/ImportExcel) PowerShell module is quite useful.
Worth mentioning that https://github.com/dfinke/ImportExcel does excel -> powershell -> excel in a really nice package for that kind of filtering/etc work.
A thing I find even more user friendly is Import-Excel https://github.com/dfinke/ImportExcel
It's a powershell module that allows you to easily dump things directly to excel files, does pretty decent datatables, multi-tabs, etc.