Ok, I finally found something I can work with:

Option Explicit

On Error Resume Next

ExcelMacroExample

Sub ExcelMacroExample()

Dim xlApp
Dim xlBook

Set xlApp = CreateObject("Excel.Application")
Set xlBook = xlApp.Workbooks.Open("C:\MyWorkbook.xls", 0, True)
xlApp.Run "MyMacro"
xlApp.Quit

Set xlBook = Nothing
Set xlApp = Nothing

End Sub

..vbs script which can be used.