I want call a bookmark in my generated HTML documentation from an external source like an article in my private company wiki site.
Sorry but that is the way it is. You would need to submit a feature request for bookmarks to survive the trip even if not used.
Please follow this link.
I notice you are using the Rh for Word forum but I suspect you are using Rh HTML. Rh for Word is a separate product rather than being a forum category for Word related matters.
See www.grainge.org for RoboHelp and Authoring tips
It's not a feature it's a bug because when i save the document as HTML from Word the bookmark as generated like anchor tag.
If i lost some information during the Word to HTML conversion in RH, it could not be considered like a new feature but like a bug.