The GlobalLabelSettings command allows the user to Globally update all Label Styles from older versions of Civil 3D to use the newer formatting codes.
Type GlobalLabelSettings at the command line, the Global Label Settings dialog is displayed. Make the desired settings in the check boxes and either select Apply these settings for any one you like to change, or select the Apply ALL Settings and Close button to apply all available settings. The command will attempt to update all applicable styles to the new settings, including existing labels with Overridden text. Note - If used in versions prior to 2011, the Digit Grouping will be displayed but will not be available for use.
At this time the items to update include the "Drop Leading Zeroes" & "Drop Decimal for Whole Numbers" for Angles and Directions, and the new for 2011 Digit Grouping settings for Distances, Elevations, Coordinates, etc.