You can make use of the UI Cultures and Localization feature to add your own keys to the CMS.resx file, as described here:
UI Cultures and LocalizationYou can access the keys from your resx file using the following method:
CMS.GlobalHelper.ResHelper.GetString(string
key,string
culture)
Where "key" is the keyname and "culture" is the culture code.
Regards,
Allen