Microsoft Word - how to copy a section without it re-numbering everything but?

still keeping the formatting? Like in a book with many chapters, I only want to copy chapters 5 and 8 and they have headings and sub-headings like 5.0, 5.1, 5.1.1, etc. If I copy them it reverts them all to 1.0 and 1.1.1 and so on and won't LET me force them to be what I want. I can paste "text only" but then it strips off all the other formatting - bolds, underlines, different font sizes - is there such a thing anymore, I know, I'm a dinosaur, as copying what is THERE, just as it is? You know, what we used to mean by COPY? I don't know when "copy" came to mean "transform", or why. Thanks for any help!