I'm sorry for my late reply because we just have a holiday.
I'm not understand your idea.
Were you created a new plugin and then you can't run it ?
How to create a plugin ? you can read here :
docs.joomla.org/J3.x:Creating_a_Plugin_for_Joomla
no, I do not want to create anew plugin. I tried two plugins for the question but cookie on your template does not seem to work.
plugins are: Cookies Pro , Folcomedia - Plugin use cookies alert
can you help me? thanks