Please navigate to the Edit Menu >>  Preferences — Application — Key Shortcuts 

You can add custom keyboard shortcuts on both Mac and Windows. 

Use the Key Shortcuts pane of the Preferences dialog box (QuarkXPress/Edit menu) to customize key shortcuts for QuarkXPress. 

Use the Key Shortcut Sets drop-down menu to choose from the existing key shortcuts sets or click on the icon to duplicate an existing set. 

Choose All to display all key shortcuts, Menu to display only shortcuts related to QuarkXPress menu items and Non-Menu to display all shortcuts not related to menu items.