Bicycle Mechanics - Shimano tiagra derailleur with Campagnolo Xenon levers

Guys, can I mix Shimano tiagra derailleur (9 speed) with Campagnolo Xenon levers (9 speed).
Is it doable without any modifications? If there are any mods to preview what are they?
if it's possible to mix and match like that that would save me some money...
Thanks for help...

The opinions about which hybrid drivtrains that can be run together varies considerably, what's good enough for some might be totally unacceptable for someone else.
Here's a link that's required reading for mixing parts:http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946#Shimergo&foo=shimano%20+%20campagnolo%2011-24-2005

The correct answer is no. If you have a Shimano 9 RD and cassette, then even Campy 10 shifters pull too much cable amd 9 speed shifters would pull way too much cable..

There is an alternate cable routing that can make Campy 10 shifters work with Shimano 9, or a J-tek shiftmate can be used. The idea of the alternate cable routing is to lengthen the effective lever arm and reduce the travel of the RD.

http://www.hubbubcustom.com/articles_ergopower.html

J-Tek shiftmate, a derailleur cable travel 'agent' ..
same sort of differential roller diameters technique.

NB there is also a freehub, Campag makes to use shimano cassettes
on what will still be a Campy hub.

Thanks for all the suggestions - now I have a few options to look into although I must say that Shiftmate seems to be the best one of them, although not the cheapest (this prize goes to Hubbub conversion, I think).
One more thing: anybody out there happens to know if Shiftmate is available in France or do I have to order it from US site?
Thanks again all of you, guys, you've been really helpful:)

If you have a Shimano 9 RD and cassette, then even Campy 10 shifters pull too much cable amd 9 speed shifters would pull way too much cable.

Perhaps an 8-speed cassette could be used? To compensate for the extra cable being pulled? But I really have no idea.

OP, do you have a Shimano hub or a Campy hub? It might just be cheaper and less hassle to sell your non-matching part and buy the "correct" one.

Using a modern Shimano derailer with a Campag 9s shifter will index properly with 6-speed sprocket spacing.

Alternatively, you can use a JTek pulley to adjust the cable travel going into the derailer. There are several versions for different parts combo's.