Welcome to KH Angelika!
There sure is a way to use 29" needles… magic loop! You may have to do single loop instead of the usual double loop, but it can be done. You can also use two circular needles if you have another one. Whichever works for you.
Magic Loop
http://www.knittinghelp.com/videos/advanced-techniques
http://tutorials.knitpicks.com/wptutorials/?s=magic+loop&submit.x=0&submit.y=0
Single loop aka traveling loop