Copy to Clipboard button

Hello!
I'm creating a pdf with instructions for users on how to insert our logo into their page. I have a text field containing HTML code that users need to copy to use on their page. I'm trying to create a 'Copy the code' button that, when clicked, will copy the HTML code to the user's clipboard. I've tried various scripts to achieve this, but none of them have worked. Is it even possible to do this?
Please help.

Thank you!