SPSS Syntax with Bonferroni Correction for a Simple Effects Analysis

My stats question for my research is:

I am running a 2x2x2 mixed Anova, between 2 groups, and with repeated measures for Control-trial (CI versus II) and Distractor-type (PosF versus NegF) to evaluate main effects and interactions on Accuracy.

The variables used for control-trial and distractor-type accuracy are: posCI_Accuracy, posII_Accuracy, negCI_Accuracy, negII_Accuracy

I have found a significant interaction between Distractor-type and Control-trial type.

The interaction plot showed that there was no difference between the negCI_Accuracy and the negII_Accuracy, however there was a difference between the posCI_Accuracy, with a rise to the posII_Accuracy.

So I would like to run a post-hoc test with a Bonferroni's correction that will tell me whether the posCI_Accuracy and posII_Accuracy results were significant.

I was thinking that a simple main effects analysis would be required because there are less than 3 levels for my factors, however I cannot seem to work out the SPSS syntax required to achieve these results.

Are you able to help me to figure out what syntax I require please?

Thank you.