Advanced Pricing - How to add a charge on Sales order header if sum of line qty is less than 10

Hi,

We are on R12.1.3

Requirement: If customer XYZ orders less than 10 units on a Sales Order, then a charge of $100 should be added at Sales Order Header level. The quantity of 10 should be cumulative quantity, which means there could be more than 1 line on the order and the sum of all line quantity should be more than 10. Only then this charge will not be applied. If cumulative line qty is less than 10, then a charge of $100 must be automatically added to the Sales Order header.

Approach:

I tried various approaches but couldn't get exact solution. Please assist with the setup.