I would like to start out by saying i am looking for a plugin only solution, i know this is achievable with woocommerce hooks and so on, but first i am searching if a solution already exists. I am searching for a woocommerce plugin that would create a custom button next to Add to cart button, with a custom text (eg. Live Demo) and the ability to add a custom link for each product separately, leading to an external page. Thank you for your time
That type of functionality is almost certainly too basic for there to be a plugin for it.
That sounds like it would be a fairly basic customisation to any theme