Code:
' I don't have a lot of experience in excel but I've
' handled littel jobbies like this
' I create a macro to do my excel work for me
' I then would call the file holding the macro
'
' of course if you need to enter information gathered
' on the fly throught your app and write it in this
' macro business is not what your are after
'
' then I would run this from my VB Application
'
'create and object (Excel SpreadSheet)
      Dim oXL As Object
      Set oXL = CreateObject("Excel.Application")
      
' Open the workbook that contains the macro to run.
      oXL.Workbooks.open "C:\Folder\MyFile.xls"
'
'as object opens invisible, make visible if needed, if not omit
'the line oXL.visible=true
'
      oXL.Visible = True
'
' Run the macro.
      oXL.Application.Run "MyFileName.xls!MyMacroName"
'
' Quit Microsoft Excel.
      oXL.Quit
'
' Free the object from memory.
      Set oXL = Nothing
'