I am using Zoho Forms to capture referrals from 3rd parties.  

The form creates a new entry in a custom module.  The person filling in the form is a contact that is linked to the custom module.  It is imperative that they are connected.

The Forms/CRM integration will allow me to populate standard fields, but won't allow me to change lookup fields.  As a result, I can't capture the person referring.

I thought I might be able to code something from CRM to find the form, capture the referrer email, search for the contact and link.... but I can't seem to find a way to access form data from within CRM. I tried Flow.... no joy.  I search for an API.... again, nothing.  What am I missing?

My current (convoluted) plan is to write a note with the email address of the referrer as the subject and, if a new record is created with the appropriate tag, search the notes for an @ in the subject.  I'm hoping someone has a better way.

Thanks

Matt