In VBScript, where you have named arguments such as 'Field:=', you need to replace the arguments in the order expected by the method, as shown below.
objRange.AutoFilter 19, "TRUE"
Also, As the Power Automate for desktop contains actions for using Excel, I suggest using the "Launch Excel" and "Set active Excel worksheet" actions to open workbook and select sheet.
The code below is a sample flow, which you can copy and paste into flow designer.
SET Rango TO $'''DataRange'''
Folder.GetFiles Folder: $'''C:\\Test\\Excel\\Files''' FileFilter: $'''*.xls*''' IncludeSubfolders: False FailOnAccessDenied: True SortBy1: Folder.SortBy.NoSort SortDescending1: False SortBy2: Folder.SortBy.NoSort SortDescending2: False SortBy3: Folder.SortBy.NoSort SortDescending3: False Files=> ArchivoExcelCopia
Excel.LaunchExcel.LaunchAndOpenUnderExistingProcess Path: ArchivoExcelCopia[0].FullName Visible: True ReadOnly: False Instance=> ExcelInstance
Excel.SetActiveWorksheet.ActivateWorksheetByName Instance: ExcelInstance Name: $'''Micros'''
Scripting.RunVBScript VBScriptCode: $'''Dim objWorkbook
Set objWorkbook = GetObject(\"%ArchivoExcelCopia[0].FullName%\")
Dim objWorksheet
Set objWorksheet = objWorkbook.ActiveSheet
objWorksheet.Range(\"%Rango%\").AutoFilter 19, \"TRUE\"''' ScriptOutput=> VBScriptOutput