Hello vegardbell

Thank you for your purchase.

Please go to ../wp-content/plugins/wpdatatables/source/class.wpdatatable.php, and you'll see two instances of 'Copy' - on line 3320 and 3391.

Please replace it with what you need, and it will show up in the plugin. So, replace this:

'text' => __('Copy', 'wpdatatables')

With something like this:

'text' => __('Custom', 'wpdatatables')

Please note that this will be overridden when you update the plugin, and you'll have to do it again.