Greetings
My first post here!
I'm looking into Vegas and trying to find out an easy way to get avs scripts into Vegas. Just found this thread today on doom9 -
http://forum.doom9.org/showthread.php?t=133313
Load the mkv in an avisynth script then do the magic with "Avisynth virtual file system" and "Pismo File Mount system" and everything should work. I'll be trying it very soon.