Here's a function you can use to get a reference to an already-open IE window (given a URL to match on)
'usage:
Dim IE
Set IE = GetIE("http://www.linkedin.com")
If Not IE Is Nothing Then
'work with IE object
End If
'Find an IE window with a matching (partial) URL
'Assumes no frames.
Function GetIE(sAddress As String) As Object
Dim objShell As Object, objShellWindows As Object, o As Object
Dim retVal As Object, sURL As String
Set retVal = Nothing
Set objShell = CreateObject("Shell.Application")
Set objShellWindows = objShell.Windows
'see if IE is already open
For Each o In objShellWindows
sURL = ""
On Error Resume Next
sURL = o.document.Location
On Error GoTo 0
If sURL <> "" Then
If sURL Like sAddress & "*" Then
Set retVal = o
Exit For
End If
End If
Next o
Set GetIE = retVal
End Function