Asking people to write a program for you won't get much of a response here (or on most development support forums).
You said that you got this working in Processing, why would you want to redo it in .NET. Nothing wrong with wanting to redo it, just wondering why.
What's not working in .NET, or what are you stuck on? While the code would be different, the concepts would be the same.
From the post on the other forum, I couldn't even begin to guess at what to write, since I don't know what your Arduino code looks like, or how you were doing it in Processing.
In short, you're going to have to post a lot more info to get some help with this.