Automatically make out-of-sample forecasts on SPSS

Hi everyone!

I'm a little stuck on a problem on SPSS and I really hope you might help me.
For my master thesis I am trying to elaborate a statistical model for forecasting Consumer Confidence time series. The model I'm using now seems to work great in in-sample forecasts, but how can I know if it will work in out-of-sample as well?

In practice, does anyone know how to set SPSS to automatically produce x-steps-ahead forecasts over a rolling window?
Let's say I divide my sample in an estimation period from 01/2004 to 08/2010 and a forecast period from 09/2010 to 09/2013. How can I make SPSS automatically adjust the estimation period one month ahead each time so that for example it will make one-step-ahead forecasts for the entire 3 years of the forecast period?

I can do it manually by gradually shifting the estimation period forward, and running my ARIMA 36 times (12 months * 3 years), but I simply can't believe there isn't a smarter way.

Please help me, this issue is seriously affecting the feasibility of my thesis.

Thanks in advance!