FCP exports video with the TC of the clip, if you In point is on 1:00:00;00 then your clip will be. Then in DVDSP you have to use asset based.
You should be able to open your scc file in text edit (open a duplicate copy), you will be able to see your CC’s timecode. The text is just alpha-numberic code.
What did the CC company view to make the CC file?
If you just drop in the video and attach the scc file, burn a disc or just build the video TS folder. Open one of these up in the software DVD Player and turn on CC. Is it working?
I’m going to be hit and miss soon so it would be better to keep this on line.