ZScript for Windows that loads any ZScript inside the folders defined in the ZBRUSH_PLUGIN_PATH environment variable.

ZBrush_ExternalPlugins_Win.txt

[VarDef, crlf, [StrMerge, [StrFromAsc, 13], [StrFromAsc, 10]]]
[VarDef, quot, [StrFromAsc, 34]]
[VarDef, temp, [FileNameResolvePath, "_deleteme"]]
[VarDef, bat, [StrMerge, temp, ".bat"]]
[VarDef, txt, [StrMerge, temp, ".txt"]]
[VarSet, offset, 0]

[RoutineDef, write,
  [VarAdd, offset, [MemWriteString, externalPlugins,
    [StrMerge, text, crlf], offset, 0]
  ]
, text]

[If, [MemGetSize, externalPlugins],
  [MemDelete, externalPlugins]
]
[MemCreate, externalPlugins, 1000]

[RoutineCall, write, "@echo off"]
[RoutineCall, write, [StrMerge, "set ", quot, "_OUT=", txt, quot]]
[RoutineCall, write, [StrMerge, "if exist ", quot, "%_OUT%", quot, " del ", quot, "%_OUT%", quot]]
[RoutineCall, write, [StrMerge, "set ", quot, "_BUFFER=%ZBRUSH_PLUGIN_PATH%", quot]]
[RoutineCall, write, ":loop"]
[RoutineCall, write, [StrMerge, "for /f ", quot, "delims=; tokens=1,*", quot, " %%G in (", quot, "%_BUFFER%", quot, ") do ("]]
[RoutineCall, write, [StrMerge, "  set ", quot, "_BUFFER=%%~H", quot, ""]]
[RoutineCall, write, [StrMerge, "  if exist ", quot, "%%~G", quot, " ("]]
[RoutineCall, write, [StrMerge, "    for /f ", quot, "tokens=*", quot, " %%I in ('dir /b ", quot, "%%~G", quot, "') do ("]]
[RoutineCall, write, [StrMerge, "      call :validate ", quot, "%%~G\%%~I", quot]]
[RoutineCall, write, "    )"]
[RoutineCall, write, "  )"]
[RoutineCall, write, "  goto loop"]
[RoutineCall, write, ")"]
[RoutineCall, write, "goto :eof"]
[RoutineCall, write, ":validate"]
[RoutineCall, write, "set _DONE=0"]
[RoutineCall, write, [StrMerge, "echo %~x1| findstr /irxc:", quot, ".zsc", quot, " > nul && ("]]
[RoutineCall, write, "  set _DONE=1"]
[RoutineCall, write, [StrMerge, "  if exist ", quot, "%~dpn1.zs", quot, " goto :eof"]]
[RoutineCall, write, [StrMerge, "  if exist ", quot, "%~dpn1.txt", quot, " goto :eof"]]
[RoutineCall, write, ")"]
[RoutineCall, write, "if %_DONE% == 0 ("]
[RoutineCall, write, [StrMerge, "  echo %~x1| findstr /irxc:", quot, ".txt", quot, " > nul && ("]]
[RoutineCall, write, "    set _DONE=1"]
[RoutineCall, write, [StrMerge, "    if exist ", quot, "%~dpn1.zs", quot, " goto :eof"]]
[RoutineCall, write, "  )"]
[RoutineCall, write, ")"]
[RoutineCall, write, "if %_DONE% == 0 ("]
[RoutineCall, write, [StrMerge, "  echo %~x1| findstr /irxc:", quot, ".zs", quot, " > nul || goto :eof"]]
[RoutineCall, write, ")"]
[RoutineCall, write, [StrMerge, "echo %~1>> ", quot, "%_OUT%", quot]]

[MemResize, externalPlugins, offset]
[If, [MemSaveToFile, externalPlugins, bat, 1] < 1,
  [Note, "Error preparing ZBrush for external plugins."]
,
  [VarDef, file, ""]
  [VarSet, offset, 0]

  [MemDelete, externalPlugins]
  [ShellExecute, [StrMerge, quot, bat, quot]]
  [FileDelete, bat]
  [MemCreateFromFile, externalPlugins, txt]
  [FileDelete, txt]

  [Loop, 10000,
    [VarSet, bytes, [MemReadString, externalPlugins, file, offset, 1]]
    [If, bytes,
      [VarAdd, offset, bytes]
      [FileNameSetNext, file]
      [IPress, "Zscript:Load"]
    ,
      [LoopExit]
    ]
  ]
]
[MemDelete, externalPlugins]

Thanks for the kind words! 😊