Hi hemantsharma!
I'm trying exactly the same.
We need to create coupons dynamically, depending on an external list.
Do you know that the Adobe Campaign already counts on a Coupon structure?
Maybe this will help you to start: Personalized coupons
This structure already picks randomly coupon values for each recipient. The challenge is just to load coupon codes to this structure without manual work.
We managed to build Coupons using javascript code and building an XML using the API documentation.
Our problem now resides in load the coupon values (the codes) to the structure. We couldn't find, yet, how to build an XML for doing this dynamic addition.
I tried to make the loading of the coupon values using the "Update Data" node in a Technical Workflow. But it doesn't seem to be consistent.
If I have any updates, I'll bring here.