call excel macro with powershell

I'm trying to open an excel sheet, run the macro and close it periodically to get an E-Mail notification when a date in a cell changes to "xxx".

Unfortuantely, powershell shows an error when running the macro below:

Sub tata(ByVal Target As Range)
  On Error Resume Next
    If Target.Cells.Count < 1 Then Exit Sub
  Set xRg = Intersect (Range("AT28:AT673"), Target
   If xRg Is Nothing Then Exit Sub
   If IsNumeric(Target.Value) And Target.Value = 1 Then
     Call Mail_small_Text_outlook
  End If
End Sub
Sub Mail_small_Text_Outlook()
    Dim xOutApp As Object
    Dim xOutMail As Object
    Dim xMailBody as String
    Set xOutApp = Create.Object("Outlook.Application")
    Set xOutMail = xOut.App.CreateItem(0)
    xMailBody = "Hi" & vbNewLine & _
                ""
    On error Resume Next
    With xOutMail
       .To = "Name@domainname.com"
       .CC = ""
       .BCC = ""
       .Subject = "order"
       .Body = "xMailbody
       .Send
    End With
    On Error GoTo 0
    Set xOutMail = Nothing
    Set xOutApp = Nothing
End Sub

Ausnahme beim Aufrufen von "Run" mit 1 Argument(en): "Parameter nicht optional. (Ausnahme von HRESULT: 0x8002000F (DISP_E_PARAMNOTOPTIONAL))" In Zeile:14 Zeichen:2 + $App.Run("tata") + ~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : COMException

 $xlFixedFormat = [Microsoft.Office.Interop.Excel.XlFileFormat]::xlOpenXMLWorkbookMacroEnabled
$app = New-Object -comobject Excel.Application
 $app.Visible = $True
 $app.DisplayAlerts = $False
 $wb = $App.Workbooks.Open("c:\my.xlsm")
 $App.Run("tata")
 $app.ActiveWorkbook.Saves
 $app.Quit()

You need to pass an argument (Target) when calling the macro :

$App.Run("tata", "value for target")