Dim path, fso, file, files
Dim wb As Workbook
path = ThisWorkbook.path & "/hoge"
Set fso = CreateObject("Scripting.FileSystemObject")
Set files = fso.GetFolder(path).files
For Each file In files
    Set wb = Workbooks.Open(file)
 
    '処理を記述
 
    ActiveWorkbook.Close SaveChanges:=False
Next file