Not knowing how to get SPM to do this, or wanting
to use a GUI interface for it, I wrote my own code.
The translation is stored in the xSPM file created when you
run results. If you run results for a given study at a very
low threshold (like p < 0.99999), it will include almost
all voxels in the rbain.
However the function only works properly for files in
2x2x2mm space. the reason is that it searches for the voxels
you specify, but I have set it to go up to the next even
number. If you want it to work for 3mm of 4mm data, you will
need to edit lines 7-9 to make sure it always gives a multiple
of the voxel size.
If that doesn't help, the data is stored in:
xSPM.XYZ % voxel space
xSPM.XYZmm %MNI space.
I hope that helps!
Colin.