Help creating custom URL

I hope someone will be able to help as I love this form.

What I’d like to do is send an e-mail with a link that when clicked will direct to my form and automatically populate populate some hidden data fields with data from the database regarding another plugin (basically i need an id to fill in automatically). I purchased the add-on but can’t get it to work the way I’d like.

Any ideas or help would be really really appreciated. Thank you.