Facilities like the one I work, offer captioning services. If you are interested I can give you contact information and more information about the technical aspects.
You'll either need to buy captioning software or there is live captioning services like Aberdeen Captioning (www.abercap.com). Aberdeen can now provides a black striped video you crop and add to an NLE but it requires a non-fire-wire card (ex. AJA KONA) to encode to tape at this time: http://www.abercap.com/ppc_nledirect.php
You'll either need to buy captioning software or there is live captioning services like Aberdeen Captioning (www.abercap.com). Aberdeen can now provides a black striped video you crop and add to an NLE but it requires a non-fire-wire card (ex. AJA KONA) to encode to tape at this time: http://www.abercap.com/ppc_nledirect.php
You need to create two steps:
1- a CC script ( eg Cheetah format) Subtitle workshop is a free program for this but takes a lot of work.
2. An encoded video - (line 21) from the script
Send it with your master to an encode facility or use a NLE with 720X486 output card and crop in line 21 as mentioned
CCaption is a program that encodes an avi from the script - equivalent to the black video version.
I'm going to let the producer deal with. That was her plan anyway, but I thought I'd try to help out. There's a facility here in town that can, as you described, take our show as a file, combine it with the script, and burn a master tape.