You can access any database that has an ODBC driver or OLEDB provider using the new ADO action in VBP 6 [1]. The attached sample should be close for the PostgreSQL's OLEDB [2] provider. If you have an ODBC driver for it, that would work too (specify ODBC in the Provider field and your DSN name).
[1]
http://www.kinook.com/Forum/showthre...?threadid=1218
[2]
http://pgfoundry.org/projects/oledb/