I am trying to do an asymmetry analysis using steps detailed in MailScanner has detected a possible fraud attempt from "secure-web.cisco.com" claiming to be https://surfer.nmr.mgh.harvard.edu/fswiki/Xhemi

However, step 1.3 starts with running:

mris_apply_reg --src lh.map.mgh --trg lh.map.lh.fsaverage_sym.mgh
--streg $SUBJECTS_DIR/subject/surf/lh.fsaverage_sym.sphere.reg
        $FREESURFER_HOME/subjects/fsaverage_sym/surf/lh.sphere.reg

What is this lh.map.mgh file? and where can I find it/how can i make it?

Thank you,

Carlos