Sync Outlook (privat) and Exchange(job) only not private marked contacts

Hi,

I have an HTC with WM 6.1 which i want to synchronize between my home pc
(outlook 2007 , windows vista ,WMDC )
and an exchange server (job) .

on my home pc i have all contacts marked as private. they were synchronized
from the pc to the ppc (that works fine) . but my problem is that they also
(when i sync)
synchronized to the exchange server (job)

how can i prevent that the as privat marked contacts / schedules not
synchronized with the exchange server ?
greetings