As with all programming problems, the first thing to do is to forget that it's a programming problem. That way, you get it out of your head that you can't do it because of a lack of programming experience. Pretend that what you actually need to do is to explain to a person how to do the job manually. Assume that you need to write down a set of steps that any person could follow to perform this task. You don't need any programming experience to do that so go ahead and do it.
Remember that I said "any" person, so you need to really break the task down into the simplest steps you possibly can. Once you've got a list of steps, look at each step and see if you can break it down any further to even simpler steps. Don't stop until you have the absolute simplest steps you possibly can. At that stage, you have solved your problem.
The final stage is to implement that solution. This is the part where programming comes into it. You can look at each step individually and determine the best way to implement it in any programming language, be it C# or something else. If you encounter a specific issue with a specific step then you can ask us about that specifically.
Don't just try to pluck code out of thin air. Even the most experienced programmers do what I've described above. The more experienced you get, the larger the individual steps can be but we all still break things down into manageable chunks when we get a complex project. That's called software development.
As I said, if you encounter a specific issue along the way then you should absolutely post about that here and I would be glad to help. If you haven't encountered a specific issue though, you haven't really given the problem enough thought. If you don't think your current learning material covers what you need then try the tutorial link in my signature below. I know for a fact that that provides all the information you would need to do your current assignment.
