How do I make the 'Pay with a like' plugin work when user submits a form?

In my site users can register using a registration form, or can post a question with Q&A plugin.
I would like they promote on their wall/profile of Fb/Lin/Tw/G+ the site when they click the register now/ask now button.
Is it possible?
May I hire someone of you to do it? ; )
Thank you in advance,