I create a new 12c composite.
The in/out to the rules is as follows -
I create a range in the rules dictionary
I create a decision table and a rule based on the amount, leveraging the range.
Now I can export this to Excel and add more rules, if required.
Note the 3 tabs in the excel sheet
Here I add a new rule for very low amounts -
I save and re-import.
The new Rule is highlighted
I click accept changes and the rule is no longer highlighted.