Loop through all .xls files in subdirectories of a directory

Sub LoopThroughFolder()
    Dim folderPath As String
    Dim filename As String
    Dim WB As Workbook
    
    folderPath = "C:\Orders\Dan\"
    
    If Right(folderPath, 1) <> "\" Then folderPath = folderPath + "\"
    
    filename = Dir(folderPath & "*.xls")
    Do While filename <> ""
        Set WB = Workbooks.Open(folderPath & filename)
        
        'Call a subroutine here to operate on the just-opened workbook
        Call YourMacro(WB)
        
        WB.Close False
        filename = Dir
    Loop
    
End Sub

'Requires reference to Microsoft Scripting Runtime

Option Explicit

Public Sub Process_Orders()
    
    Dim Fso As Scripting.FileSystemObject
    
    Set Fso = New Scripting.FileSystemObject
    Process_XLS_Files Fso, "C:\Orders"
    
    Set Fso = Nothing

End Sub


Private Sub Process_XLS_Files(Fso As Scripting.FileSystemObject, folderPath As String)
   
    Dim Folder As Scripting.Folder, Subfolder As Scripting.Folder, File As Scripting.File
    Dim wb As Workbook
    
    Set Folder = Fso.GetFolder(folderPath)
    
    For Each Subfolder In Folder.subfolders
        For Each File In Subfolder.Files
            If InStr(File.Name, ".xls") Then
                Debug.Print File.Path
                'Open File.Path workbook here and call your code on it
            End If
        Next
    Next

End Sub