how to add Excel program to Windows 10 iCloud?
I have an iPad and a Windows10 laptop. Excel is listed in my iCloud app as "on". How do I add Excel to iCloud in Windows10 so they will sync?
iPad 2, iOS 9.3.4
Where exactly is it listed?
Excel is a Microsoft App and would not appear in iCloud at all. Do you mean Apple's Numbers?
If you have the Excel App for iPad, you can open documents stored in iCloud Drive with it.
From your Windows 10, you can drag and drop files to the iCloud Drive folder in Explorer if you have iCloud for Windows installed.
On your iPad (this image was taken in the Word app, but works the same in the Excel App for iPad):