how to restore a backup of single mailbox/folder with many subfolders without disturbing the other mailboxes

[Robert Noll]

Hi all,

i'd like to ask for advice on how to restore a backup of single mailbox 
without disturbing the other mailboxes.

Let's say user albert deleted an important folder with many (100+, 
hierarchy) subfolders accidentally.
A complete system backup from yesterday evening is available,
but i don't want to restore the whole mail-system to the state of yesterday
because that would mean other users would loose anything that has 
happened since then (sent, received etc).

Following some info i found,
i created a new mailbox folder for the user in the mailsystem  
(albert/myrestore)  ,
restored the files from the backup system in there,
and ran   reconstruct -r albert/myrestore

while the mails directly inside the folder are now visible correctly,
the subfolders are not visible,
any idea how to solve this ?

please advise =)
Regards,
Robert Noll