Clipboard functionality in email template

I want to send a coupon code in the email template. A Small button that will copy the content of a input element on the clipboard.

By email Template, i mean i want to send a email which will have a coupon code and there will be a button in the email template which will allow me to copy it to clipboard. Can this be done?

Any help will be appreciated.

Considering that javascript cannot be added inline to the email template, i couldnt think of any other solution.