From the forum, I was told £200 for a replacement - dealer only piece.
Anyway, went to a very helpful national company dealing in hydraulic hoses who were aware of the cost of a Citroen part but said that they could make one up for £25 - 30.
After discussion with them, I cut the metal pipe 10mm away from furrel at pump side of flexy pipe and took it to them along with the piece of pipe from union in inner wing.
For £15.99 I have a proffessionally made up piece of flexi pipe to metal pipe to existing flare joint and compression fitting to pipe from pump.
Got new spheres from GSF and following forums guide have another smooth Xantia.
Thanks
Malc