title: Log4Net: How to add simple indexer (row number) to each log line
body: <p>Here is the problem:
  I want to add row indexer (row number or iterator) to each row in log file.
  I don't need it to be unique for the whole log file, but only for the "application session" (i. e. each time Win32 application started, we begin our countdown: 1, 2, 3 and so on)</p>
  
  <p>Is where any built-in way (conversionpattern tag syntax) or some custom extension?</p>
  
  <p>Thanks a lot!</p>