Try this link to OpenOffice and its postgres-sdbc-driver.
http://dba.openoffice.org/drivers/postgresql/
I have Installed OO on RedHat and tested that I can connect postgres -
which it does without any dramas, but I havent done much more than that.
So I am not sure as to what the limit is on the complexity of the
queryies asked of it can be.
It doesnt connect via either odbc or jdbc, and currently it is in alpha
state, which might not be what you are after. But it could be worth a
look at.
Cheers
Matt