Remap M code

When I remap M708, define my M code as required:
[RS274NGC]
REMAP = M708 modalgroup=10 argspec=ABC ngc=m708
And put m708 in:
SUBROUTINE_PATH = ../../linuxcnc/nc_files/gladevcp_lib
In the directory, but I tested my M code in linuxcnc MDI: M708 A123 B456 C789, linuxcnc cannot execute it and told me that M code>199.
How should I set this up?
Thanks in advance

My m708.ngc:
o<m708> sub

(debug,A word= #<A>)
(debug,B word= #<B>)
(debug,C word= #<C>)

o<m708> endsub

M2

My M708 code:
#!/bin/bash
#The value of the output parameter

echo "A=$1"
echo "B=$2"
echo "C=$3"

exit 0

User defined codes are M100 to M199
linuxcnc.org/docs/2.8/html/gcode/m-code.html#mcode:m100-m199

Thanks for your reply, but M100-M199 only has two parameters P and Q; I need to recreate or remap an M code to realize the identification of the three parameters.

I am using linuxcnc.org/docs/2.8/html/remap/remap.h...xample_remapped_code and try it with M400, linuxcnc can output the values of p and q, but my remapped M708 cannot be executed.

I found my problem, my configuration file was wrong, now it's solved
 

I succeeded in remapping an M code, but I cannot execute the shell script while executing the M code.I want to execute my script while executing the remapped M code. I need to pass parameters in the script, get this parameter?
My settings：
[RS274NGC]
SUBROUTINE_PATH = /home/zyz/linuxcnc/nc_files/gladevcp_lib
REMAP =M708  modalgroup=10 argspec=PQR ngc=mytest
My code:
mytest.ngc:
o<mytest> sub
(debug, P word=#<P>)
(debug, Q word=#<Q>)
(debug, R word=#<R>)
o<mytest> endsub
M2
After linuxcnc executes the M code, the output will be displayed in the lower right corner of the interface, but it is not displayed on the Ubuntu terminal.
M708:
#!/bin/bash
#input 
echo "P=$1"
echo "Q=$2"
echo "R=$3"
exit 0

 

When I use the python script to remap an M code (M708), I cannot receive the parameter value input by MDI. How can I get the parameter value input by MDI?
axis.ini:
[RS274NGC]
# File containing interpreter variables
PARAMETER_FILE = sim.var
SUBROUTINE_PATH = /home/zyz/linuxcnc/configs/sim.axis/python/toplevel.py
REMAP = M708 modalgroup=10 python=m708

[PYTHON]
TOPLEVEL = /home/zyz/linuxcnc/configs/sim.axis/python/toplevel.py
PATH_APPEND = /home/zyz/linuxcnc/configs/sim.axis/python

toplevel.py:
#!/usr/bin/python
import sys
import remap 

remap.py:
#!/usr/bin/python

import sys  
from interpreter import *
from Tkinter import *

def m708(self,**argv):
    print(sys.argv)


 

I found my mistake:
def m708(self,**words):
for key in words:
print("word '%s' = %f" % (key, words[key]))