Schema for Custom XML Markup

[Lauro]

In my Word 2007 documents there will be a Table with 2 columns and many rows.
In each rows the first cell will contain just the number of a numbered list;
the second cell will contain one or more paragraphs with text but maybe also
pictures or others.

I want to tag with my Custom XML Markup:
a) the table
b) each rows
c) each cell
d) each paragraphs in the second cell
e) some run in the paragraphs of thesecond cell.

I'm writing MySchema.xsd but I'm having problems in choosing the right TYPE
for the elements I'm creating.
I was imagining that I could include a reference to the WordML elements and
put "cell", "table", "paragraph(s)" as types.
Is it possible? And how?
The validation dosn't have to be very strict.

Thanks, Lauro