This article does appear to show how to create and set a cookie in server-side C# code. I'm guessing in the DNN environment, I would have to build a custom DNN module to add to each page of the website that would examine the URL of the page while it loads, and if the Rakuten query string parameters were present, would grab and use those values to build and set the cookie during the page load.
I was hoping that there would be some similar DNN module out there I could review to understand better, but right now it looks like a ton of effort for a very limited ROI value. Anybody have any thoughts or ideas?
I've mostly associated HTTP Response Headers with security and authentication messages sent to the browser, rather than marketing cookies.
I was hoping to find some example of a DNN project that I could use as a foundation for that, but the only DNN modules I find around the topic of cookies are "Cookie Consent" modules to meet GDPR requirements.