Online Help:

Usage: /vol/vssp/local/trees/amma-4/linux/bin/exregis [options] 
   -optload () [] Load options from a file.  
   -optsave () [] Save options to a file.  
   -jacob (0) [0] Test the Jacobians 
   -svd (0) [0] Test the SVD routine 
   -i (1.vec) [1.vec] input  filename .vec
   -w (1) [1] enter weights 
   -s (0) [0] enter noise 
   -t (1) [1] enter transformation 0 or 1 
   -c (0) [0] enter reg_type 
   -r (0) [0] 0=dont apply reflect, 1=apply reflect 
   -help (TRUE) [FALSE] Print usage information.