Request an Approval from Email address in specific cell



I am needing some help. I am having a team member fill out a form, that form needs to be approved by several people. However it seems that the "Request an approval" needs to be a specific person (which wont work because each form will be different users", or Send to contacts in a cell, however it seems that the contacts in a cell must be a "Contact List" not just an email. Does anyone know if there is a way around that or if I were to integrate an Active Directory it could pull from there rather than entering in hundreds of Names in the "Contract List".

Any advice or help would be greatly appreciative.

Thank you!