Address Location of outlook express

I do not work much with outlook express so i was surprised when i could not find location of the address book.
In Outlook 2000 the addresses are stored either in .pst or .pab file.
What is the location of the outlook ones?
Do they require manual registry editing?
what i am looking for is to share the same address book in multiple profiles. It is easy in outlook 2000. Is it possible in outlook express?