I don't have a batch to do them all, but I DID write a batch to bypass having to open the command prompt while decompressing some Klonoa files.
Here, put this inside a .bat file inside the same folder as your ntcompress.exe. Just make a .txt, put it inside, and rename the file to .bat.
ntcompress -x %1
Then just drag your files to be decompressed onto it. Makes things much easier.
EDIT:
Also, I could've swore RandomTalkingBush already figured out most of this stuff at the Modeler's Resource though. Unfortunately, I can't find the thread.