Before going to lunch.
>As to the new method, ask yourself to what part of your application is it specific? If it is a method to enhance rule classes generally, you could create an IvanRuleClass, add the method there and base all other rules on your IvanRuleClass, thereby adding the new method to each and every rule instance.
Reading the Manual (don't shout), I just found out Calc1 , Calc2 and Calc3 methods in the cmRule to be used whenever needed.
From CM Help: "Using these empty placeholder methods means you won't need to create a special rule subclass just to add a couple of your own methods for custom code."
Later.
Ivan