I am not sure about the DPBC part of it, but to get the Zip + Zip4 to work,
you will have to use
{BARCODE {QUOTE {MERGEFIELD ZIP}"-"{MERGEFIELD ZIP4} } }
Quite likely
{BARCODE {QUOTE {MERGEFIELD ZIP}"-"{MERGEFIELD ZIP4}{MERGEFIELD DPBC} } }
will give the whole thing.

Signature
Please post any further questions or followup to the newsgroups for the
benefit of others who may be interested. Unsolicited questions forwarded
directly to me will only be answered on a paid consulting basis.
Hope this helps
Doug Robbins - Word MVP
> I am trying to get Word 2003 to print the entire Delivery
> Point Barcode (Zip + Zip4 + DPBC)in a merge document, but
[quoted text clipped - 9 lines]
> Anyone have any ideas on how to get this to work in
> Word2003???