Commande IF en BATCH ne veut pas fonctionner :'(

ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Vérifie la présence de token >> Log.log

:TOKEN
 ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Vérifie la présence de token >> Log.log
 IF NOT EXIST "token.tkn" (
  ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Aucun token trouvé >> Log.log
  CLS
  (
  batbox /c 0x7
  )
  TYPE %msg_02%

  (
  batbox /c 0x2
  )
  SET /P b=
  IF %b%== retour GOTO CHEMIN
  ECHO %b% >> token.tkn
  .\exe\Base64Convertcmd /c 0 /l 0 token.tkn token.tkn
  ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Écrit et encrypte le token >> Log.log
  GOTO DL
 ) 
 ELSE 
 (
  ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Token trouvé >> Log.log
  (
  batbox /c 0x7
  )
  TYPE %msg_04%

  (
  batbox /c 0x2
  )
  SET /P e=

  IF %e%= oui GOTO OUI
  IF %e%= o GOTO OUI
  IF %e%= y GOTO OUI
  IF %e%= non GOTO NON
  IF %e%= n GOTO NON

  :OUI
  ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Décrypt le token >> Log.log
  .\exe\Base64Convertcmd /c 2 /l 0 token.tkn token.tkn
  FOR /F %%a IN (token.tkn) DO (
   SET %b%=%%a
   ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Récupère le token décrypter >> Log.log
   .\exe\Base64Convertcmd /c 0 /l 0 token.tkn token.tkn
   ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Réencrypte le token >> Log.log
   GOTO DL
  )

  :NON
  DEL token.tkn
  ECHO %date:~0,2%/%date:~3,2%/%date:~6,4% %time:~0,8% ^| Supprime le token en mémoire >> Log.log
  GOTO TOKEN
 )