Customizable PowerForm Email Subject (No mergefield)

Hi DocuSign community,

We have a form that is a powerform so it is initiated from our website. There are dozens of these forms being initiated per day. The person that the form is for is not in the signing order (and cannot be in the signing order due to privacy) so their name cannot be added to the email subject line via mergetoken. The envelope custom field does not work because the administrator would need to change the field before every envelope is created. I propose that there is a way for the subject line in powerforms/webforms is customizable to add someone not in the signing order. 

Thank you Eduardo from DocuSign for trying to help me with this issue!