SPM inverse transformation matrix, how to transform standard ROI to Native space?

Question

I am trying to transform a standard anatomical atlas ROI to each subject's native functional space. For reasons, I used SPM to preprocess my data. I am new to SPM and cannot seem to find where the transformation matrix from normalization and coregistration was stored. In fsl, there is an inverse transformation matrix computed during preprocessing that you can then use, usually called standard2example_func.mat. Does SPM compute this same matrix, and if so where is it? If SPM does not compute and store this, is there an easy way to create it short of re-preprocessing some 60 odd subjects in fsl? Thank you in advance, and apologies if this is a naive question.

I notice in the first-level outputs from SPM there is the SPM.mat file. I have looked and also seen SPM.xVol.M and SPM.xVol.iM. If I compute the inversion of these would it be the equivalent of fsl standard2example_func.mat?