Ideally you do this through a module, but it brings many details that are not the focus at the moment.
Note that the Block you are trying to change is part of the core and is on:
app/code/core/Mage/Adminhtml/Block/Catalog/Product/Edit.php
There in the builder is executed: $this->setTemplate('Catalog/product/Edit.phtml');
I believe that’s the view you want to manipulate.
Then for the action of the button, you would direct to a controller of your module, where the prefix would be configured in its config.xml. For more details, see the Magento module fonts on Github.
I will indicate 2 that I had some contact, where in the first I put a chargeback button on the administrative page of order details:
You need to give more information, show the code you are using and show the part where you have trouble so that someone can help you. There are thousands of ways to do what you want.
– Pedro Gelli
There is a lot of information missing...be more specific...are you using any programming language? is the content generated dynamically? post an example code...
– Kenny Rafael
I need to know, how you define the route and how I mount the Block so that I insert a button in it and it appears in the product editing page in adminhtml calatog product tab
– Rodrigo