I haven't seen this mentioned anywhere so I thought I would comment... I had a similar issue myself, where the bat file would report that the EXE was a bad path or could not be found. It seems to me that it's an issue in Vista (god I hate this OS), even running the bat as Administrator wouldn't add the local directory to the PATH.
1. Extract the patch to the same directory as your rom
2. Rename the rom to xpa-lzst.nds
3. Manually open a cmd prompt
4. CD to the directory all your files are in
5. Run xpa-zstc.bat from the command line.
Done! Rather than error trying to find the exe, you'll notice it pause as it's processing the file. The script will properly process the rom and create the -cracked.nds version for you. Cheers!
