What you are looking for is the Cross Reference field { REF BookmarkName } which reproduces the content of a bookmark. Note that REF fields don't update automatically so allow for this in the macro that writes to the bookmark.
e.g. Call the example code at
http://www.gmayor.com/installing_macro.htm
As for writing to bookmarks, see the FillBM function at
http://www.gmayor.com/useful_vba_functions.htm