Converting an AS2.0 file to AS3.0?

Hey everyone,

I have a CS3 file that was given to me to make some changes to.
It was written in AS2.0, but I would like to implement some new AS3.0 classes.
Is there any way to convert this file to an AS3.0 file? I’d really like to avoid re-creating the entire .fla.

Thanks in advance for any thoughts!