Ah, I see. Well - there are a couple of options.

1. You can get flash and work on it that way.

OR

2. This one is all dependant on how the actionscript is currently compiled and written.

As long as all of the actionscript is one 1 frame of the flash file...aka (one page) You can create an external .as file and do an include to the actionscript file in the flash file. That way you could manipulate the AS upload it to the server, just like you could do with a .css file seperatly from the .html or.php/.asp.

It's look something like this:

#include "myAs.as"

Make sense?