Yes and no
There is no automatic way of handling this for an existing document. You need to insert the bookmarks and the cross references initially and then the cross references will reflect what is in the bookmarks.
Had this not been for the Mac version of Word I would have suggested that you send me a copy of the document so that I could get a better handle on the document format to see if there is a better solution, but I don't have access to the Mac version.
If you are able to attach a version with personalisation removed to the forum (Go Advanced) other Mac users may be able to offer some alternative suggestions.