Seems like I've been replying to old threads, but since it's been about 3 months, if anyone's interested in c3 file editing, I remember Ultimation had a viewer. Links are dead but you can probably google or ask someone if they have a copy of the file(although this is just to view whatever you edited). There's also this tool:

found from

but I've never toyed with that.
If someone still has this file though:

would be great if you could share.