[rules-users] Help on writing drl in excel file

Dear Sir Thanks for the answer by the way is there any way to slove my free item problem . I want to make a decison table in excel where my client will fill in the item and free item list as Purchased ITem No of purchase Free Item No of free ========================================================== Pen 2 Rubber 1 Pen 5 Pencil 1 Pen 10 Pencil 3 Pen 12 Pencil 4 Ink bottle 3 Sticker 1 Ink bottle 5 Sticker 2 Ink Bottle 10 Sticker 5 When a customer buys 19 pen then his free item will be 4 pencil (due to first 12 pens) 5 pencil (due to remaining 5 pens) 1 rubber (due to 2 pens) I have been trying to write the rule and fit into excel since from 1 week but due to my limited knowledge of drl and decision tables in excel it is taking a lot of time than writing code with lookup table and JAVA if else Please help me to slove this riddle Thanks Niraj