See http://word.mvps.org/FAQs/MacrosVBA/NumberDocs.htm ,
http://word.mvps.org/FAQs/MacrosVBA/NumberCopiesOf1Doc.htm , and
http://word.mvps.org/FAQs/MailMerge/NumberCopiesOfDocMMerge.htm
for several methods. If you don't know how to install a macro,
then see http://www.gmayor.com/installing_macro.htm .
> I'm trying to print multiple copies of a document, but I want each copy to
> have a sequence number field that increments from the copy.
>
> As if each copy of a letter had its own serial number.