Hi,
There are two different things:
- social sharing : This can be done with the HikaShop social networks plugin. It will add facebook/twitter/etc buttons on the product details page of the products on your website. When someone will click on one of these buttons, it will allow them to share the product they are looking at on the social network with their account there.
- affiliation : This will provide the users with HTML they can add anywhere accepting HTML. People using the link they added will be counted as their affiliates and they can earn a commission on the sales made by their affiliates.
Facebook doesn't access HTML when posting a message. So you can't directly get the HTML of the affiliation to post it on Facebook.
If you want to post an affiliation link on Facebook, instead of the HTML, you need to copy/paste the "Link".
Regarding your last question, what kind of form are you talking about ? A registration form ? A contact form ? I'm not sure I have the full picture of what you're trying to do.