How to get the Numbered Headings as in word using c# code.

Question

I created the buttons like NumHeading up to 1 to 5. If i click the button one i want to dispaly like this "1" second button "1.1" third buttton "1.1.1" so on up to button 5. Please send code for this in c#. I am wating it is urgent.

 

I want to display the custom functions for Numbered Headings list as in word