OpenFire as some kind of proxy

We have one Openfire server on LAN but we would like to give access to this server for Internet users. We do not want yet to open Openfire protocols on firewall [no so safe solution]. Is there any solution to set up two servers where sever in DMZ relays connections or proxy Spark connections to Openfire server on LAN?

I think in standard server to server settings we have configurations where two servers have databases for users and both belongs to different domain. Such configuration does not fulfill what we need.

Any advice?

Thanks for help,

Gosf

Maybe this will do http://www.igniterealtime.org/projects/openfire/connection_manager.jsp

Thanks a lot for advice.