I currently operate a .com website. I am looking to register a .de domain but I want it to forward to my .com domain.

Sounds easy enough... however I don't just want it to forward to mysite.com I need it to redirect to mysite.com/affid394 (so that an affiliate on my network can earn commission on my sales) They are our distributor in the target country.

How would this effect my SEO? Because it would not be the same URL, would Google see it as duplicate content? Or would they simply see it as a .de domain being redirected to my original .com domain. (note it won't be a separate site, same site... different URL)

I hope I have made sense and I know this is a tough one!

Greatly appreciate all advice I am given.

Brett.