I have subscribed to office all of a sudden on my lap top the EXCEL icon came on as a ?

Hello, thank you for using Howly. I’ll be happy to help you out! May I ask your name?

Nice to meet you, *****!
To change the icon of a shortcut:
Right-click the shortcut in Windows Explorer.
Select Properties from the context menu.
Click 'Change Icon'

This is Windows Explorer
It has a File Icon

You need to "right" click it.

Okay
After pulling up Finder > Applications, find the app you'd like to change the icon for. Right click and select Get Info or use the keyboard shortcut command + I. Now just drag the new image you want to use on top of the existing icon (you can also copy the new image then paste it onto the existing icon).
Control-click on a Mac is similar to right-click on a Windows computer—it's how you open shortcut menus on a Mac. Control-click: Press and hold the Control key while you click an item. For example, Control-click an icon, a window, the toolbar, the desktop, or another item.

Please use my steps above to fix that.

On your Mac, select the file or folder. Choose File > Get Info in the menu bar. At the top of the Info window, select the small custom icon. Make sure you click the small icon at the top of the Info window Please download the Excel Icon from Google