[Koha] batch mode Z39.50 client

Hi, I've just installed Koha 2.2.6 successfully on Ubuntu (6.06 LTS) and I'm trying to figure out how to migrate the 6000 records from our old DOS based library system. As our current records are pretty basic I'd like to enhance them by using Z39.50 to download MARC records from public servers. I've managed to get the Z39.50 client working using Koha's Intranet web interface but it seems this only does one biblio at the time. Is it possible to quiry a list of ISBN numbers on multiple Z39.50 servers? If this is possible, I wonder, would it then somehow still be possible to keep our current local Call-Number when using MARC records from different Z39.50 servers? All the best, -- Jochum