[FieldTrip] Coregistration using fixed fiducials coordinates

[Rasha Haider]

Dear fieldtrip experts,
Im trying to do source localization for simulated EEG data, for this I followed the tutorial in page:
http://fieldtrip.fcdonders.nl/tutorial/minimumnormestimate

I was trying to use the mri image provided by fieldtrip (Subject01.mri) and EEG template (standard_1020.elc) in my work.
The mri image need to be re-aliened to the Talairach space for coregistration with EEG space. In the tutorial you use (ft_volumerealien) to do that using interactive method.
I have two questions:

First, how can I do the coregistration using fixed coordinates of the 3 fiducials (nasion, left pr, right pr), in other words how can I get the coordinates of the fiducials in both Talairach and EEG spaces to do the coregistration using the script only not manually.

Second, I tried to use the mri image provided by the spm toolbox because its already aliened to Talairach space, but when I try to do segmentation I get error that coordinates field does not exist:

??? Reference to non-existent field 'coordsys'.

Error in ==> ft_volumesegment at 284
  original.coordsys  = mri.coordsys;

Error in ==> segmentation_spm_mri at 24
seg           = ft_volumesegment(cfg, mrirs); 

I read the image using (ft_read_mri) function, I don't find the field specified for the coordinates:

disp(mri)
          dim: [177 240 256]
      anatomy: [177x240x256 double]
          hdr: [1x1 struct]
    transform: [4x4 double]
         unit: 'mm'

How can I solve this problem so I can use the mri image in SPM for further analysing in fieldtrip?

Sorry for the long email I would be thankful for any help.
Regards
Rasha 
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