How to add html content into the lead view

I wrote a server side plugin. For Microsoft Dynamics online CRM.

that registered to the "retrieve" message, with the "lead" entity information.
This plugin is being called when the user is trying to view information on a lead.

What i am trying to do is to be able to push a full html content (with css, image, and all) to a section of that lead view.
Is that possible?

Thanks