Hi Daniel -
If you start off by selecting a row item when you click on the Totals Grouping toolbar icon it will control the way the columns are grouped, so you could choose 'At End'.
Alternatively, you can do a fully ad hoc ordering. SImply Ctrl Select the columns in the order you'd like and them and then choose Format > Show Selection. They will appear in the ad hoc order.
Cheers, Adam