Adding "reviewer" to signature request

Sorry - this is going to be a rather lengthy set up. 

Scenario:  I have a document requiring signature from a person.  That person has an "assistant".  The assistant wants to be included as a "reviewer" on all signature requests sent to the person, but doesn't want to be required to sign the document.  What the assistant wants to do is receive the request for signature, review the document, click on something to send to the person who is supposed to sign the document with a note something along the lines of "reviewed; ok to sign".  I haven't been able to find anything specific to that.  The only thing I cound was CC, but that doesn't allow for the auto forwarding of the document to the person signing the doc.  Thanks.