NWNNSSCOMP (
http://www.lucasforums.com/showthread.php?t=145516) is able to both Compile and De-compile.
Sure, it requires use of the command prompt, but it does the job...
...just make sure you're able to use the Command Prompt before Downloading.
How: Start-->Run-->TYPE: cmd
If it pops up and looks like a weird version of DOS than you're good!