Assuming Fiery and not Freeflow:
In CWS5 go to the job properties and select Media
Enable the Slip sheets and the tray and size to be used
Scroll down and define the Chapter Starts and enable the Seperate Finishing Set option
That should work, if not, disable the Slip Sheets and use New Insert instead, then just define where in the job to put them (Probably 1 page previous to each Chapter Start)
http://help.efi.com/fierydrivermac/4.8/en-us/GUID-8FFB2203-8C3C-4049-9B6D-520E2C427A43.html
http://download.support.xerox.com/pub/docs/XRIP_700DCP_Base/userdocs/any-os/en/Workflow.pdf