One easy method to share any web radio via UPnP on your network is to use the gst-launch plugin. This is a simple rygel.conf snippet to expose NDR Info to your DLNA enabled devices. For other services I’d first try to replace the uri and the content-type accordingly.

[GstLaunch]
enabled=true
launch_items=ndrinfo
ndrinfo_title=NDR Info
ndrinfo_mime=audio/mpeg
ndrinfo_launch=souphttpsrc location=http://ndr.ic.llnwd.net/stream/ndr_ndrinfo_hi_mp3