"mediated moderation" using GLM in SPSS

How to run a "mediated moderation" using GLM in SPSS
I was not sure about the "control " portion for the final step to establish the moderation.
THANKS So much in advance
yes, of course

here are the variables.
first, X is a categorical three -level IV
Y and V are continuous. Y is DV, and V is a moderator. X and V interacts and jointly influence Y.
I want to say M (mediator) is mediating the interactive effects of X and V to Y. So, the whole picture is mediated moderation.

The question is how to test this mediated moderation in GLM. what are the steps? Thanks