batch-upgrading documents 5.5.6 to 7.2?

[Jakob Fix]

Hello,

well, we've almost finished our migration software-wise, now we need
to convert several hundreds documents to the new version.

instead of opening each and every file manually, being told that it's
a version 5 document, and agreeing to have it updated by clicking the
OK button in the dialogue box, isn't there a "silent" way of
opening/upgrading files?  I wouldn't mind doing it on a per-book
basis, because we have meta books containing all files of a
publication.  Also, I know about the Shift+File click which shows
"Open all files in book" etc menu items.

So, to restate my question, is there a "silent option" to open files
created in a previous version in 7.x?

--
cheers,
Jakob.

PS: I guess one could save the old files in MIF, and load them in 7.x,
but how can this be automated?  DZBatcher?  Any other ideas?