I have Word 2000. It's not something I have ever tried to do, but I suspect not.
It might be possible with a clever macro, (beyond my skills!) but a bit brutal... (something triggered when the cursor is between certain bookmarks... copy the relevant bit, store it, then paste it back)...
Given that the text isn't to be changed, perhaps a more suitable method would be for the relevant text to be an inserted graphic?...
This would bring 2 disavantages... the graphic could be deleted, and it would make the file larger.
I don't know, but perhaps text boxes can be "locked". Perhaps the relevant text can go in a text box?
I'll watch this for any other suggestions.