Как программно заполнить поля формы на сайте и нажать на кнопку submit(Go)?

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hWnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Public Function CShell(ByVal URL As String) As Long
   CShell = ShellExecute(0&, vbNullString, URL, vbNullString, vbNullString, vbNormalFocus)
End Function

Private Sub Command1_Click()
   m1 = "http://www.google.com/search?client=opera&rls=ru&q="
   m2 = "&sourceid=opera&ie=utf-8&oe=utf-8"
   msg = m1 & "Shearsh string" & m2 ' между m1 и m2 надо поставить строку поиска.
   Call CShell(msg)
End Sub