Finally I've found how to put xml or html tags in the CodeHighlighter. Post has to be escaped,
So convert ">" into ">", "<" into "<" and so on...
I have found also good online tool with which this is much easier to achieve:
http://www.freeformatter.com/xml-escape.html#ad-output
If I am writing Joomla! article without any text editor and if I want to show ";gt;", then I should write it like "&gt;" :)