To add a mouse button combination
- Click Tools
tab
Customization
panel
User
Interface.
At the command prompt,
enter cui. - In the Customize User Interface Editor, click the Customize tab.
- In the Customizations In <file name> pane, click the plus sign (+) next to Mouse Buttons to expand the list.
- Right-click
a mouse button section. Click New Button.

A new mouse button (named Buttonn) is placed at the bottom of the selected list.
- In
the Command List pane, drag the command you want to add to the mouse
button in the Customizations In <file name> pane.

- Click OK.