'Upgrade Membership' For CCBill Programs In Members Area?

Does anyone know how such a feature would work, for example, lets say we offered a limited trial access on a paysite (for arguments sake) and wanted to offer the surfer 'full' access to the members area for an additional $X a month, which would then rebill at the full monthly rate.....

How would one go about getting that setup so that the affiliate was credited with the 'upgrade' sale inside the members area?

Do any of you folks that run a CCBill based affiliate program offer something like this and, if you do, how did you handle making sure that the affiliate who sent the initial trial join, also got credited with their share of the 'upgrade' fee and subsequent monthly recurring membership?

Regards,

Lee

I'm not so sure that's currently possible with CCBill. If it is, I too would be curious to know how to do it.