Hello Rodrigo Arques Palacio,

I am really sorry for the delay of this reply as it is a weekend for us here.
Let me know if i getting wrong with your requirement, do you mean that put a comment link in Joomla Article frontpage right? See my screenshot : http://screencast.com/t/qjZN1M0t
If no, can you elaborate your question with more details, and include a screen shot of what you are referring to, also provide with your Joomla backend as well? Please advise.

Not exactly, i'm referring to the link in k2 article view pointing to the komento form, we would like to add it to the joomla article view, take a look:

That "be the first to comment" link changes to 1 comment when someone posts a comment.

Hi,

If you relying on Komento, then currently Komento only have the option of displaying a link bar in listing pages that states the number of comment of the article. You can enable this at Komento -> Integrations -> Joomla Article -> Layout -> Frontpage.

If you are looking for the exact same thing from K2 on Joomla's Article's individual article page, unfortunately Komento doesn't provide such feature.