postgres replication only some datas

Hello,
a question about a tool or a possibility how could something work.

following situation:
we have a database which is full of very sensitive information and needed that db to use our online website.
but now we move the website to a server outside our office and needed to replicate only some datas to the online db.
with the tool slony i found out , that some tables could be replicated, but in some tables are some information, which we do not
wont to replicate.
so we need a tool or an idea how to do that.
I though about a dump and deleting the sensitive datas, but the database is about a half gig and we need the changed entries
directly on the online db within seconds.

Anybody how could help?

Greetings
Matthias