I have run into a recurring problem that I suspect it can be fixed
with either a field or a cross references; I just do not know how to
do it.  Any help would be appreciated.

Many legal documents use numbered paragraphs, and it is often
necessary to refer to previous paragraphs by their number.  Simple
cross references work most of the time.  However, some common
documents are split into sections, and each section has to expressly
incorporate the prior sections by references.  The result looks like
this:

SECTION 1
1. blah
2. blah
3. blah

SECTION 2
4. Plaintiff refers to and incorporates herein by reference,
paragraphs 1 through 3 above, as though fully set forth herein.
5. blah
6. blah

SECTION 3
7. Plaintiff refers to and incorporates herein by reference,
paragraphs 1 through 6 above, as though fully set forth herein.
8. blah
9. blah

I have a user-defined paragraph style for the numbered paragraphs, and
I use the heading styles (modified) for the section titles.  For now,
I am using cross references that point to the previous numbered
paragraphs.  Unfortunately, I usually edit the document after I create
the references, and I occassionally delete the paragraph that the
reference points to or add a new paragraph after it.  Both situations
cause problems for the references.  Deleting the paragraph causes the
field to show an error message, and adding a new paragraph to the end
of a section causes the reference at the beginning of the next section
to display the wrong number (because the reference now points to the
wrong paragraph).

Is there a way to make a field display the number of the numbered
paragraph immediately preceding the current one, even if that
paragraph later changes in the ways I described?