HASP. Network key. How to define several Expiration Dates for the same Feature?

Question

I'm thinking how to implement following task using Aladdin HASP SRM APIs. I'll explain on specific example.

HASP Network Hardware Key enables to run 10 copies of application concurrent (HASP Key enables 10 licenses).

Each license enables 1 Feature. Feature has Expiration date.

Problem: Expiration Date will be the same for all 10 licenses. I have to control the same Feature by 3 different Expiration Dates:

• Date1 for 3 licenses
• Date2 for 4 licenses
• Date3 for 3 licenses.

Why: because User paid maintenance a year for 3 licenses, 1.5 year for 4 licenses, 2 years for 3 licenses.