Extending a series by a moving average

[miorinnovo]

Is there a command that will automatically add a moving average to the end of a series? For example, if I have annual growth data from 2000 to 2012 and I want to take the average of the 2009-2012 and add it as the 2013 data point, as well as taking the 2010 to 2013 average and add it as 2014?

thanks!