Unfortunately, I don't know a way of doing this. However, when I have worked in a program that didn't support the chapter marks I needed, I just made a quick list of the chapter timecodes, and enter them into Encore. If you select the timeline, and click in the timeline timecode readout, you can type the timecode numerically without any punctuation, and it jumps you right to the spot. If you then right click on the curser and choose add chapter point, you can do a couple dozen chapter points in a couple of minutes. Not as nice as direct conversion, but it's also not very time consuming, and I'd much rather suffer the minor inconvenience than have to work in DVDit.