I would say you should be using Outline numbering styles instead of the
same. It's very much like my explanation of creating a test or quiz;
however, there I have them numbered, where you can put text in front instead
of numbers, using all the same methods.
http://www.officearticles.com/word/tests_and_quizzes_in_microsoft_word.htm
I hope it helps!

*******************
~Anne Troy

www.OfficeArticles.com
www.MyExpertsOnline.com

Hi Waleed

If you want to share the numbering sequence, with different prefixes, you
would be best using a field for the number. You can either use a SEQ field
or a named LISTNUM field. SEQs need to be updated when you insert or delete
within the sequence. LISTNUMs will update automatically but use the somewhat
less robust autonumbering (as in numbered styles).

The trick you are using is bound to lead to problems if you copy and paste.
It sounds like you are managing to get a separate List for the thm (if
highlighting the numbers is really showing all the thms) but in that case
you must effectively be setting the numbers by hand. This is going to fly
apart!

If you decide to use a separate numbering sequence for ex and thm (more
logical, in my opinion) then all you need to do is set up two separate
styles, each with its own numbering.

Complications arise if you want to use the built-in heading styles as these
always link to their "matching" outline level. So you will need to use level
4, say, for the ex sequence and level 5 for the thm sequence, but unset the
"restart after" level so that each continues unaffected by the other.

On your specific questions, you could use a macro to step through all
numbered paragraphs and test the format, but I don't think it is worth the
effort, especially as you will need to reapply a style to the ex sequence as
well as the thm. I would use Outline View to proof through the current
Heading 4s, then apply the appropriate style to each.

For more information on how to set the styles up safely, see

http://www.shaunakelly.com/word/numbering/OutlineNumbering.html

If this were my document, I would paste a copy into a fresh document shell
after tidying up the styles to lose what by now must be a rats' nest of List
Templates.

--
Margaret Aldis - Microsoft Word MVP

Assuming that you want theorems and examples formatted with the
Heading 4 style, I'd suggest that you leave this style unnumbered, and
instead manually type "Example" or "Theorem" (whichever is required)
and use a SEQ field for the numbering.