Jane, I agree with Bill (about embedding it into the DVD). The DVD spec permits subtitles very easily.
If you’re going through the keying route, two thoughts.
1) You’ll have a long import, unless you’ve directly rendered into one of the avid codecs or a camera codec (like DV25)
2) The spectramatte keyer will allow you to ‘knock out’ the green.
Best,
Jeff G
Principal Instructor
Future Media Concepts
FMCTraining.com
Editorsretreat.com