Hi,
I have a very long document (500+ pages) that is currently peppered with phrases like this:

"as we discussed in Chapter 12, on page XXX,"

... and I'm planning on filling in the XXX's later. But I just know that I'll be adding and subtracting text, and the pages will change as I modify the document.

What's a good way to handle this? I picture having some field or identified location with each XXX in the text, and perhaps at the very end of the document an area for me -- something like:
page where I explain A and B: ____
page where I explain C and D: ____
... and I'll fill in just those areas, and the correct page will magically appear in the text everywhere it's supposed to.

Is there a good solution for this?
Thanks in advance for any help.
--Steve D.