If i miss anything kindly add it. I'll say it in quick terms.
1) Make your system run on "japanese" locale.
2) there are two files, just use "agth.exe" , and choose the target of your game
eg. "C:\Games\Nitroplus\ChaosHead\ChaosHead.exe"
-do not forget to include the file extention which is exe"-
3) Append to the start of "Target" field
eg. "C:\AGTH\agth.exe" "C:\Games\Nitroplus\ChaosHead\ChaosHead.exe"
-space in between is needed-
4) now run the shortcut that you've made with AGTH
This is the simple way of running the game. but there are a lot of codes or options you can do with AGTH like "/C" to automatically copy text clipboard eg. "C:\AGTH\agth.exe" /C "C:\Games\Nitroplus\ChaosHead\ChaosHead.exe" -with spaces in between-
i tired to look for online help with the correct options to run the game properly.
-hope this helps-