Seems that the only possibility is to thread the cable hose out and then in again through the other holes…ugly work, I mean.
“handlebar adjustment” - Hmm, maybe better to use “handlebar locking lever” or “handlebar lever”, I believe 
These posts might be helpful:
http://www.stridaforum.com/forum/viewtopic.php?f=2&t=3406&start=0&st=0&sk=t&sd=a
[url]MK1 professional restore? (steering)]