You can use
Webcam Timershot from the
Microsoft PowerToys. You can set it to save directly into the temporary folder which stores files waiting to be written to a CD.
I, too, am not sure how you would write files to a CD as it takes the pictures. However, it wouldn't be efficient at all to write the files one at a time. You would be writing a file table each time and all the file tables (pretty much duplicated over and over again) would take up most of the space on a CD. 60 or 70 megs would be usable for pictures, max.