Send Email to Dynamic Third Party and copy administrator

I want to use dynamic fields to send an email in the manner described here http://www.gravityhelp.com/documentation/page/Using_Dynamic_Population

That is the form will enable a user to contact a third party (of which there are lots). I need the form to also email the administrator. Ideally I'd send the user a different notification email as well.

What's the recommended approach?

I can see that I could put {admin_email} in the copy field, but how do I get the dynamic email field in to the "To" email notification field. This doesn't have a drop down. Can I use a shortcode like {my_form_email} or do I need to write some php to trap the query string myself and use a hook that you no doubt have?

I'm asking how to do it, so no I don't have a link yet. I'm new to GF but very familiar with PHP and Wordpress development. What I'm after is in principle the same as that note in your documentation, but I'm not clear on the best way to implement it.

I want to set up one form which will be used for users to email different suppliers on the site. Each supplier will have a listing which will have a contact link/button that passes information on to the web page holding the form using the $_POST

I was planning on generating the form in the template using gravity_form(..., $thisformdata), but if there's a better way then do tell me.

What I need to know how to do, is how to get that forms notification to pick up the supplier email address in the admin notification To email field.

I'll use the notification cc field to copy in the wordpress admin using {admin_email}

My issue is that in the form creation, the admin notification "To" field does not have a drop down to select a field that I could populate dynamically.

So I wondered if
1) There's a kind of generic shortcode/tag that would reference a dynamic field that I could use (i.e. {supplier_email} where that's the name of the email field in the form. But I'm now thinking that GF doesn't work like that.
2) I do presume you have a hook to let me change the admin notification To email data.

In a nutshell, I'm asking what is your recommended way of getting an email address from a dynamic field on a form into the admin notification "To" email data.