I must give a publish to my Wordpress based blog (my very own hosting) from outdoors of the blog using PHP. In a nutshell terms i must make a move such as this:

http://www.mywebsite.com/addPost.php

Adds example publish to my blog and thats all i want. How to get this done?

WordPress implements numerous APIs to permit this: http://codex.wordpress.org/XML-RPC_Support

Additionally to xml-rpc support, you may be thinking about the "Press This" functionality:

http://codex.wordpress.org/Press_This