You need to do something like this to set the object. I simply just ran the macro recorded within SAP to get the code below. If you can get this to work please let me know because I have been struggling with trying to write code that allows excel to talk to SAP. Does your SAP open via citrix as well?

If Not IsObject(application) Then
   Set SapGuiAuto  = GetObject("SAPGUI")
   Set application = SapGuiAuto.GetScriptingEngine
End If
If Not IsObject(connection) Then
   Set connection = application.Children(0)
End If
If Not IsObject(session) Then
   Set session    = connection.Children(0)
End If
If IsObject(WScript) Then
   WScript.ConnectObject session,     "on"
   WScript.ConnectObject application, "on"
End If