In NAV 5.0 you have Export to Excel / Import from Excel for example in 'General Ledger - Budget - Functions'. This is not present in NAV 2009. This functionality is based on Table 370 Excel Buffer, which uses variables of type Automation to CREATE and use an instance of EXCEL.
Now I use 370 Excel Buffer extensively for reporting. It still works in NAV 2009 Classic Client, buy I can't get it working in NAV 2009 RTC. The NAV Server is running on the same PC as the client (my desktop, actually). I get an error when I try
CREATE (XlAPP, TRUE, TRUE) in RTC.