[Koha] Items migration along with records

[Frédéric Demians]

 > but how do all other people do it? people all over the world who use
 > koha use marcedit for this thing. but may be I'm posting in a wrong
 > place, because it is not a koha problem anymore.

You may be in the right place. There are a lot of MarcEdit experts here.
I suggest you to search thoroughly the list archive:

   http://markmail.org/search/?q=koha+marcedit+952

A response to your question may be already there. I also suggest you to
send a new question to this list with a new subject focusing on your
specific need.  Something like: Using MarcEdit to create biblio records
with repeatable items in 952 tag...