As it was explained to me. First go into settings>deck preferences and check assemble edit for digital cut. Set your record machine time code for at least 30 sec or more to where you want the timecode to start. IE if you want your show start to be 01:00:00:00, then your code should be set to 23:59:30:00.
Record black on your tape and be sure it goes past the 01:00:00:00
mark. Insert your tape into the tape machine hooked up to your avid, select digital cut, then enter your desired start time and set in and after the pre roll, it will start on your desired start time. I also think you have to set your timeline start time to the same value as your desired pre show time.