VBA to Select Multiple Files when one is too long

Sub LoopAllExcelFilesInFolder()
'PURPOSE: To loop through all Excel files in a user specified folder and perform a set task on them
'SOURCE: www.TheSpreadsheetGuru.com


Dim wb As Workbook
Dim myPath As String
Dim myFile As String
Dim myExtension As String
Dim FldrPicker As FileDialog


'Optimize Macro Speed
  Application.ScreenUpdating = False
  Application.EnableEvents = False
  Application.Calculation = xlCalculationManual


'Retrieve Target Folder Path From User
  Set FldrPicker = Application.FileDialog(msoFileDialogFolderPicker)


    With FldrPicker
      .Title = "Select A Target Folder"
      .AllowMultiSelect = False
        If .Show <> -1 Then GoTo NextCode
        myPath = .SelectedItems(1) & "\"
    End With


'In Case of Cancel
NextCode:
  myPath = myPath
  If myPath = "" Then GoTo ResetSettings


'Target File Extension (must include wildcard "*")
  myExtension = "*.xls*"


'Target Path with Ending Extention
  myFile = Dir(myPath & myExtension)


'Loop through each Excel file in folder
  Do While myFile <> ""
    'Set variable equal to opened workbook
      Set wb = Workbooks.Open(Filename:=myPath & myFile)
    
    'Ensure Workbook has opened before moving on to next line of code
      DoEvents
    
    'Change First Worksheet's Background Fill Blue
      wb.Worksheets(1).Range("A1:Z1").Interior.Color = RGB(51, 98, 174)
    
    'Save and Close Workbook
      wb.Close SaveChanges:=True
      
    'Ensure Workbook has closed before moving on to next line of code
      DoEvents


    'Get next file name
      myFile = Dir
  Loop


'Message Box when tasks are completed
  MsgBox "Task Complete!"


ResetSettings:
  'Reset Macro Optimization Settings
    Application.EnableEvents = True
    Application.Calculation = xlCalculationAutomatic
    Application.ScreenUpdating = True


End Sub

Sub Test()
    Dim myFile, i As Integer


    myFile = Application.GetOpenFilename("*.xls*", , , , True)
    
    If IsArray(myFile) Then  '// 2+ files selected
        For i = LBound(myFile) To UBound(myFile)
            MsgBox myFile(i)
        Next i
    Else '// Single file selected
        MsgBox myFile
    End If
    
End Sub