[Samba] Equivalent to ADUC attribute editor under linux?

[Thoralf Söldenwagner]

I would like to use the "maxStorage" attribute field as quota_rule field 
for dovecot as my new mailserver will authenticate against my samba domain.
But I don't want to edit ~2000 accounts in ADUC!

So, is there something similar for linux or a command I could use in a 
script to edit my user accounts?
Thanks for any suggestions
Thoralf