Remember to back up any file prior to modifying it.
You need to modify a file located at this location on the Computer where the Active Roles MMC Console is installed to customize the Find Columns:
The filename is "Active Roles" with no file extension. You would need to open the file as a XML to modify it. The file you find is specific to the User that is logged in to the Computer at the time.
If you copy the file to another User's Profile location and then open the Active Roles MMC Console as that User it will show the Column changes that were made to the Find dialog.