[Koha] Marc-->CSV - alternative to MarcEdit?

[hansbkk at gmail.com]

I'm trying to export batches of records from MARC to a delimited text
format, do a bunch of editing and then convert back to MARC.

MarcEdit works great, except when going from MARC to CSV, the
repeating fields (5XX and up) are being concatenated with semicolon
separators into single fields. I'd like to keep these as separate
repeating fields, so I'm working on kludging up some workarounds, but
in the meantime can anyone suggest an alternative tool, ideally one
that will do a clean round-trip, i.e. reconstruct the MARC from the
CSV identically if the data isn't altered?

Chris I'm cc'ing you specifically because I recall your mentioning a
script in a past thread that went the other way (CSV to MARC), but
unfortunately couldn't find the message in the archives.