The screen that comes up is of the double list box variety. To access the configuration screen for the Ribbon toolbar, open a new workbook in Excel and then go to the Preferences menu and select Ribbon and Toolbar.
Add/Remove Commands to the Ribbon Toolbar
Please note that these instructions are for the Office 2016 version of the software. Now that MS Office has become the standard for office applications on the Apple Macintosh OS, too, let’s discuss how to customize the Excel toolbar on a Mac. Most of the blog posts that deal with customizing the toolbars on Microsoft Office products are written for PC users.