Product Listing to show custom HTML

Is it possible to have custom html content in a panel just like a product in the Product Listing Page?
I'm using Hikashop btw, for example, to have on the product listing page, 1st product item followed by custom content then 2nd product item, etc..

Hi,

custom html content in a panel ...

we talk about back-end or front-end?

Can you show me Mock-up, it will help me understand your concept.