[Dovecot] many users maildir access

Hi All, Is it possible when using Dovecot and MySQL to tell dovecot maildir:%h/MailDir -- Yes I know but please read on before you answer this one :->

We have users directories layer structured because of the filesystems 32k directory limit , eg: user foobar@example.com's home mail directory is: /mailhosts/example.com/f/fo/foo/foobar

I know Dovecot takes maildir:%d/%u/MailDir but as you see this will not work, so I guess I'm after the defination of %h, is that home as in system users home, or home as is like our setup? Or, is there yet another way we could have Dovecot access the users mail, we need to ove away from our current setup as it is just to slow, and I know dovecot has a 30 fold increase on speed over it from talknig to other people, but none of them do anymore then the /domain/user setup so cant help me.

Regards, Vic