Affiliate System

We have designers who create custom designs, I will create products for these designers, but I want to setup a commission system where the designer will receive a % of each sale. I've tried to set this up with the built in affiliate system, but it seems that in order to get credit for a sale, the affiliate must drive the traffic.

Is there a solution for an affiliate/user to get commission based on sales of a certain category or products regardless of whether they sent the traffic?

I think the Multi-Vendor edition would do what you need it to do

I've looked into the multi-vendor package, but I don't want the person to have access to upload products or fulfill orders. We will be uploading the products and doing all fulfillment. The only thing the person would need access to is sales reports for the specified products.