Affiliates recurring commission

We would like to pay our affiliates the same recurring commission once a year.

For example, if a subscriber signs up on Jan 12, 2014 for a $20 plan, we want the affiliate to be credited $20 every year starting on Jan 12, 2014 as long as the subscription is active.

How can we do this? Or is this feature in the works? If not, can you suggest this to your developers?