Rebate set up For volumes

Hello,

I am looking for Rebate set up for Volumes.

Ex: For an ITEM ( 1 CA = 12 EA)

My Rebate set up should work for Every CA, customer is eligible to get 7 USD per CASE

Now i place an order for 2401 EA, so system should calculate 2401/12 =200.08 CA

So 200*7 = 1400 USD should be my rebate for that customer

Looking for the solution..

Thanks

Maneesh