Strange script behavior

#RequireAdmin
Opt("ExpandEnvStrings", 1)
Opt("ExpandVarStrings", 1)

Local $bak = ClipGet()
Run(@ComSpec & " /c " & 'fnr --cl --find $bak$ --replace D:\ --dir %USERPROFILE%\sosttext --fileMask *.* --silent', "", @SW_HIDE)

FOR %%n IN (D E F G H I J K L M N O P Q R S T U V W X Y Z) DO IF EXIST %%n:\partizionedati.txt SET DiscoD=%%n:
findstr .. %DiscoD%\dati.txt |clip
start %DiscoD%\myscript.exe