Posting existing contact details to a form based on previous submission

Asking this question for/with Julia Teske to support one of our event marketing staff's query to us. They want use to create a form to capture email address and then upon submission

1) If contact exists in Eloqua, pre-fill form with details

2) If contact does not exist, present blank form

This is based off of the questions listed below. I know that Stacey Schneider did this on my old team but we were using E9 as listed in the question from 2011. We're trying to find out if it's possible in E10.

Display a Contacts record if they are existing Contacts in Eloqua from submitting e-mail address in previous Eloqua form

Anyone have ideas?

Thanks!