How to Add additional Custom fields into the ContentListFactory ca

Hi,
     I am currently trying to retrieve more information using 
CSFLoadDiscounts.
i.e. the HTML text content that come with the discount.
    According to the do***ent, I can add additional custom fields into the

ContentListFactory cache by overriding the default query for
CSFLoadDiscounts.

    But Currently I really do not have any idea how to access the default 
query for CSFLoadDiscount. 

    Anybody has any idea how is this done?


howey