Is there a plug-in or native way to lay down audio timecode on an audio track in Vegas 4? (If necessary I'll upgrade to 5, but since I'm in the middle of a project, I wanted to wait.) I need to do this for my composer to work with.
You can't in 4 or 5. You can record SMPTE tone on a track, and then read it, but Vegas can't generate it. You'll need an external generator.
Why not just give him a sync click or tone?
What is your composer using to compose?