Auto-subscribe but not auto-create

Hi,

is it, somehow, possible to auto-subscribe a folder IF it exists but
NOT auto-create it if it doesn't exists?

We have folder 'Spam' which we are using to store messages marked as
spam but users are not subscribing to it (most of them simply don't
know what it means to subscribe a folder) and are complaining about
missing e-mails (which are in 'Spam' folder but they don't see them).
Even more, some users don't want from us to move spams into Spam
folder so our sieve scripts are set to move spams into INBOX if 'Spam'
folder doesn't exists (such users simply remove 'Spam' folder - this
is why we don't want to auto-create it).

Thanks.