Hi Adam,
Thank you for your update.
In Microsoft Word we navigate to the specified bookmark content and edit the contents or insert comment. For your reference we attached the video illustration for the same. Please find the video demo from the below link.
Video Demo:
Can you please refer the attached video and confirm us whether your requirement is similar to this? If your requirement is different please share more details. So that we can analyze it further and provide you the appropriate solution at the earliest.
Regards,
Emmima.