>>Do you mean that you want your log entries to appear in one of the existing sources such as 'Application'? If so it's just a question of setting the EventLog.Source property. e.g:

 Dim el As EventLog = New EventLog()
>>        el.Source = "Application"
>>        el.WriteEntry("Oops")

>
>What I mean is this new section that appears, as shown in the attached image.

Ah. That's a Windows 7/Vista Event viewer (which supports an extensible tree of logs)?
I don't know. Just a guess : try setting the EventLog.Log="Applications and Services Logs" but I assume you would also have to create your own source.....