Thanks Dodger, this is a very informative thread. At the risk of sounding stupid, I must admit that for one mad moment I thought this technique might accomplish the imposible and add a new channel to a cr2 in play. My logic ran like this; you can use a read script in a cr2 to read in a channel, you can put a read script statement into a pz2 and the contents of the script will be inserted into the cr2 when the pz2 is applied. So put a channel into the script file and use the same technique as you outlined for MATs to inject the contents of the script. I have tried this and it does not seem to work. Looks like a pz2 can only inject the things that a pz2 can inject, whether they are in a read or not. Oh well the imposible is still imposible, never the less this read script looks like it has interesting potential.