Promotional Deals

If I'm running a promotion, and want my sales order to show this info below when creating a a New Sales Order. Below is an idea/example of what I need to create in Zoho but am having problems creating this:

QTY: 3 master Cartons (2 Tropical Punch and 1 Blue Raspberry) and show the Special Discount after the Sub-Total, showing the deduction of -$216.00, and the Grand total having it at $432.00 instead of $648.00?

Can someone please let me know how we can do this within Zoho.

Thank you,

Nader