Migrating an account to another dbmail instance...

hello folks,

I've been looking around for a solution/tool that will help me migrate 
an account from one dbmail instance to another. What I want to achieve 
is to migrate an account from one dbmail instance to another completely, 
including ACLs, filters, auto-replies etc...

That being said, tools like imapsync doesn't help here. Also, both 
dbmail instances have users already in-place, so using something like:

# create table export_users as select * from dbmail_users where 
user_idnr = <IDNR>
# pg_dump --table=export_users --data-only --column-inserts dbmail > 
export_users.sql

for all relevant tables would not work because of db key/id conflicts.

could someone point me to the right direction or shed some light on 
this? I believe writing a custom tool would do the job, but really is 
that the only option I have in this situation?

thanks