Reordering effects in Effect Parade

I'm working on a script that duplicates a layer many times and adds a "set matte effect" to the new layers. I'm also copying all the effects from the source layer and pasting them to the new layers using the executeCommand method. I would like to have the set matte to be the first effect so that dropshadows etc would work correctly. Even when I add the set matte in code first and then do the paste executeCommand, the set matte effect ends up being the last effect. Is there a fix for this? Or is there a way to reorder the effects in the Effect Parade? PropertyIndex doesn't help as it is read only. 

Thanks!