I need a C# program for logging values

Hi,
I need a c# program that allows a user to select different sets of variables and write values of it timely to a log file.
The solution needs 2 things:
- an .exe with an XAML screen to select and edit different instances of a class channel and save selections with a name, time interval and an 'enabled true/false' to a LogEntries.xml file. (channels are loaded from a config file, I can provide cs that does that.)
- a loop that (when enabled) saves the name and values of the selected instances in LogEntries.xml to logfiles. (1 file per set of channels, 1 entry per time interval e.g. every second, 1 file per day). I want the code for this loop in a separate dll.

I run VS2012 express.
Thank you.