Hi,
I can't answer to that as I don't understand what you mean.
Your messages seem to imply that you have another way to access to the product page on your website and that you only want to change the template when using a specific set of instructions to access the product page. Is that the case ? If so, what are the other ways to access the product page ?
I don't even know if "Category list" in your message is a menu item or a module, if "Product list" is a sub menu item or another page of the same menu item as the categories listing, if "Product page" is a sub menu item or another page of the same menu item as the products listing, etc.
And you didn't provide a link to the shop.
So basically, I don't know your situation and thus your question is too vague to be able to say if there is a solution, even though we ask for details when you create a new topic on our forum.
That's why I can only gave a generic answer.