After spending precious at-work time on this, I think I have all the bits and pieces to put a VB program together. I just have to load VB on my home computer since I haven't touched VB in over a year. Let's hope it comes out OK.

Stupidly, I didn't bring any of my flac files to work and the sample file I'm using has the ID3v1 tags all screwed up. Writing ID3v2 tags seems to be working in VB, but the Winamp plugin doesn't support ID3v2, so who knows....