How to Define the Payment Priorities in Purchase order Level?

Hi Experts,

As per Management requirement, for example while make the purchase order the specific supplier against we given the payment terms is 30 days. But, at the time of po creation we need to capture the payment priorities as 7 days. Based on the details system will proceed the payment process 7 days instead of 30 days.

Regarding this well in advance payment, supplier offered purchase discount as per Section 194R.

How can we achieve it in standard functionality.

Thanks

Babu J