Is this change made to the same field of your record in every case?
Is Oldtext and NewText the same values used in every record?
If so, you can use replace field contents with the calculation option.
Substitute ( YourTable::YourTextField ; "cm3" ; ccm )
Could be the calculation used with this tool. Just show all records or perform a find for all records that contain cm3 first.
Note: Since this tool an modify data in very large numbers of records all in one batch operation, make a back up copy of the file first so that you can try again if the operation changes your data in ways you didn't expect.