To my knowledge your only choices are:

1. mdbtools - does not work very well. Usually used when the mdb is stored on Linux but it might work via SMB. I cannot recommend it though.
2. an ODBC bridge like the one you found - but I'm not aware of any free ones.
3. DBD::Proxy http://search.cpan.org/~timb/DBI-1.607/lib/DBD/Proxy.pm. Only slight problem is it does not support all of the DBI features.