IPX Proxy

Hi,
we`ve got new routers (Layer-3 switches) which don`t supports "IPX/SPX".

Unfortunatly we have some DOS 6.22 clients which use IPX to connect to our
Netware 6.5 Server.

These clients are difficult to change (maschines in production-line)
they have to load/ and save configuration files from the network.

Have you any idee, how can we manage this?
Is there a kind of IPX-Proxy which tunnels the IPX-packets in IP and
forwards it to the Netware server?

Thank you very much.

Lothar