Automatically subscribing to comments « Gravity Support Forums

So I'm using a Gravity Form (collecting email address etc) and I want the submitter to automatically receive notifications of any subsequent comments left on their post.

I'm coming at this from originally using TDO Mini Forms in conjunction with Subscribe to Comments plugin.

I basically hacked the TDO form which gave me access to the php of the whole form where I simply pasted the following code into the form. This code uses the functionality of Subscribe to Comments but automatically adds the submitters email address rather than them having to do it themselves:

<fieldset>
Vous serez automatiquement informé par e-mail des commentaires de suivi à votre demande. Vous pourrez vous désabonner après que le message est publié.<?php if(tdomf_widget_notifyme_show_email_input(2)) { ?>
			<?php $sc_email = $subscribe_to_comments_email;
			if(!isset($subscribe_to_comments_email)) {
				if(isset($_COOKIE['comment_author_email_'])) {
					$sc_email = $_COOKIE['comment_author_email_'];
				} else if(isset($_COOKIE['tdomf_subscribe_to_comments_widget_email'])) {
					$sc_email = $_COOKIE['tdomf_subscribe_to_comments_widget_email'];
			 } } ?>
			<br/><label for='subscribe_to_comments_email' class='required'>Courrier électronique pour la souscription commentaire (requis): <input type="text" value="<?php echo htmlentities($sc_email,ENT_QUOTES) ?>" name="subscribe_to_comments_email" id="subscribe_to_comments_email" size="40" /></label>
		<?php } ?>
	</fieldset>

	<!-- notifyme start -->
	<fieldset>
	<label for='notifyme'><input type='checkbox' name='notifyme' id='notifyme' checked='yes'  style="display:none;" /></label>
			</fieldset>
	<!-- notifyme end -->

So my question really is can I either:

1) get access to the underlying php Gravity Form code in order to insert similar code above - and probably not just the php shortcode, but the underlying code for the whole form

2) Is there a Gravity Form PHP widget that I can drag/drop onto the form to insert similar code that way instead?

3) Is there a Gravity Form widget that integrates with a similar comment subscribing widget?

Thanks

Duncan