Can be done with the messenger api, just sadly not with the api that plus imports
VB2008 Implementation:
code:
Public WithEvents msn As MessengerAPI.IMessenger
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
msn = New MessengerAPI.Messenger
Dim msnwnd As MessengerAPI.IMessengerWindow
msnwnd = msn.Window
msn.AddContact(msnwnd.HWND, "test@hotmail.com")
End Sub