Absoluted Encoder but Move the G53 Origin

Hey, I need some help.
   I have configured a machine  using LinuxCNC, and the joints are equipped with absolute encoders. Now, I want to achieve the following: Point A is the zero-count position of the encoder, but I would like to set Point B, which is offset 200mm from Point A, as the G53 origin. How should I configure this?

Here is my ini configure:
[JOINT_1]
TYPE = LINEAR
MAX_VELOCITY = 1200
MAX_ACCELERATION = 2000
#       MIN_LIMIT = -10.0
#       MAX_LIMIT = 10.0
HOME = -10
HOME_ABSOLUTE_ENCODER = 2
HOME_OFFSET = 35
HOME_SEARCH_VEL = 0
HOME_LATCH_VEL = 0
HOME_IGNORE_LIMITS = NO
HOME_USE_INDEX = NO
HOME_SEQUENCE = 1
VOLATILE_HOME = 0

But the problem is when I homing the axis, the joint->motor_pos_cmd whill change suddenly.  which cause the joint move suddenly. It is particularly dangerous.

Thank you for ur help!
    

I think that HOME_OFFSET is the parameter that controls this. (you probably want to make HOME and HOME_OFFSET the same, or possibly one the inverse of the other) 

I modified the homing.c to get it.

If you want to make this “stick” through upgrades then note that you can define your own custom homing module. ((This may be what you did)

linuxcnc.org/docs/html/man/man9/homecomp.9.html