There is not a pre-defined keyboard shortcut for Recenter Origin (also available in the Modeling menu). However, there is a Recenter button in the Button Bar, directly above the modeling window.
You could also define a hotkey for Recenter. You can create your own hotkeys for many of the commands and functions of Design 3D CX 7, using the Keyboard Shortcuts command in the Edit menu. Some users set the Recenter hotkey to Command or Control-2.
For more information see Chapter 23 - Keyboard Shortcuts in the User Guide.