Adapt existing ARIMA parameters (SPSS Output) to Excel based forecast -- 2

I am currently trying to reproduce ARIMAX forecast functions in Excel based on parameters caclulated by SPSS. I need support by someone who understands ARIMAX models and is able to adjust the current Excel solution for some specific examples (with actual data). The goal is not to identify the models, but to find a way how I can use existing models for a forecast in Excel. Based on the result I want to be able to adapt the equation in Excel to other ARIMAX models. So I will also need some support in case I have questions. I managed to set up a template for an AR(2) model (using explanatory variables also), but I can´t find a solution for the MA term. The problem seems to be that the noise residuals from the original forecast are needed. You can find a detailed description of the task and the working Excel sheet for the AR(2) model uploaded. Furthermore you can find an exemplary SPSS file that I used to set up the models. I already discussed the topic in a forum (maybe this helps) [login to view URL] As it is written in the answer in the forum it might be necessary to switch to R for model building instead of SPSS. This could be a solution, but it is preferred to find a solution with SPSS. An expert should be able to help in few hours. Input is needed by the end of this week. Further tasks might follow. Thanks in advance!