[IRtdServer interface method] RefreshData(TopicCount) [Description] 
After a call from the IRTDUpdateEvent callback object's UpdateNotify method, this method is called by Excel to pull new values from the real-time data server (also known as a topic refresh). This method returns a two-dimensional array of Variant values. The first dimension represents a list of topic IDs; these topic IDs map to the TopicID parameter in the ConnectData method above. This is how Excel associates topics with data. The second dimension represents the values associated with the topic IDs. The TopicCount parameter is a required Long value that the RTD server provides; it represents the number of elements returned in the array of Variant values.