Goal: permit clients to bulk load data into an XML aware Excel workbook on
the Web that would validate the data against a schema, providing feedback to
the submitter, for subsequent transmission behind a firewall to an Oracle
database.

Is this possible? What are the obstacles - security, other?

Currently, users dump their data into Excel templates, then validate using
Excel vba routines, then FTP to a swap drive where the files are transmitted
to Oracle.

Thanks for your help.