A family of Microsoft word processing software products for creating web, email, and print documents.
Yes you can do that but it is not intuitive, Insert Comment is on the Insert Ribbon, but is not there in the dialog to change the keyboard shortcut. . .
Click File - Options On the resulting dialog in the Customize Ribbon Tab at the bottom click Keyboard Shortcuts - 'Customize'
In the left pane select Review Tab In the right hand list scroll down and select 'Insert Annotation' You will see the default Alt + Ctrl + M Enter your required keys in the box on the right Click Assign and close the dialog