You write your logs in the system log not in "log viewer".
The concept of category is hard to understand. Please see my code where I created a wrapper designed to categorize the logs; in this approach you can have a separate folder for your product featuring more then one application. The logs for your product will go in the same separate folder, but each application will be categorized. It is good to work this way as you can see the order of logs from different applications if they communicate.
Here is the code:
How to create event log under a folder[
^].
Sorry, this is C#, but you won't have any problems understanding it.
If your goal is somewhat different, it does not matter: there are only two levels of hierarchy anyway.
—SA