I'm composing a document in Word 2003 where I have one or more appendices
with subsections, and have defined new heading styles as follows:

Appendix A (style named "Appx", outline/numbering level 1)
A.1 (style named "AppxSub1", outline/numbering level 2)

I want to have caption numbering in the appendices linked to the level 2
heading (AppxSub1), like this:

Figure A.1-n

where n is the sequence number in the respective subsection. I followed the
description in http://word.mvps.org/FAQs/TblsFldsFms/AppendixCaptions.htm,
which suggested a caption code similar to this:

Figure {STYLEREF "AppxSub1" \s }-{ SEQ AppxFig \* ARABIC \s "AppxSub1" }

My problem is the second part of the code; the sequence number does not
restart at the custom level 2 heading (AppxSub1), but seems to be totally
independent of the headings altogether. The only way I am able to restart
the numbering is to create a new sequence (e.g. AppxFigA2), but that's not
very elegant.

Does this mean that it is impossible to make a sequence number that restarts
at a given heading level, unless it's a built-in heading (e.g. Heading 2, in
which case the last "AppxSub1" would be replaced by 2), or is there
something wrong with my field code?

Kind regards
dOinK

PS: I know I could use and redefine the built-in heading styles (e.g. above
level 5) for appendix headings, that's not the solution or answer I am
looking for here (it has some unwanted consequences related to the outline
level)