You may want to try using ShellExecute instead so you can explititly pass parameters.
VB Code:
  1. Option Explicit
  2.  
  3. Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, _
  4. ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
  5.  
  6. Private Const SW_SHOWNORMAL As Long = 1
  7. Private Const SW_SHOWMAXIMIZED As Long = 3
  8.  
  9. Private Sub OpenSomething()
  10.     ShellExecute Me.hWnd, "Open", "C:\Test.xls", "/something /somethinglese /3", "C:\", SW_SHOWNORMAL
  11. End Sub