Hi
I have no experience with FW and AS/400 together, actualy I work with FWH and AS/400 separately, but I think we need:
1.- To configure the AS/400 as Server
2.- Then we can atack DB2 with FWH, (x)Harbour and ADO
3.- Obviously we need an ODBC connector, pls take a look to this link
http://www.connectionstrings.com/Regards