Transferring progress notes from one eCW clinic to another

Question: Has anyone found a method for moving a patient population’s progress notes from one eCW system to another? (I.e., all of one doctor’s charts.)  Having changed clinics, I was promised that my charts would be easy to transfer over to my new clinic’s eCW.  Not true in the least, according to our consultants. In fact, it seems not to be possible.  Note that I am not talking about data elements, or lab, or patient documents.  Also note that I have tried P2P and it is impossibly slow for this purpose.
Thanks for any suggestions.