How to map dynamic path parameter in Haproxy - haproxy

Question

I am trying to pass dynamic value based on user_id in haproxy for my java Rest Services.
localhost:/AAA/BBB/{userid}
Following Statement are example
localhost:/AAA/BBB/1
localhost:/AAA/BBB/2
localhost:/AAA/BBB/3
I want to pass it through haproxy . I have following configuration..
global
log /dev/log local0
log /dev/log local1 notice
chroot /var/lib/haproxy
stats socket /run/haproxy/admin.sock mode 660 level admin
stats timeout 30s
user haproxy
group haproxy
daemon
# Default SSL material locations
ca-base /etc/ssl/certs
crt-base /etc/ssl/private
# Default ciphers to use on SSL-enabled listening sockets.
# For more information, see ciphers(1SSL).
ssl-default-bind-ciphers kEECDH+aRSA+AES:kRSA+AES:+AES256:RC4- SHA:!kEDH:!LOW:!EXP:!MD5:!aNULL:!eNULL
defaults
log global
mode http
option httplog
option dontlognull
timeout connect 5000
timeout client 50000
timeout server 50000
errorfile 400 /etc/haproxy/errors/400.http
errorfile 403 /etc/haproxy/errors/403.http
errorfile 408 /etc/haproxy/errors/408.http
errorfile 500 /etc/haproxy/errors/500.http
errorfile 502 /etc/haproxy/errors/502.http
errorfile 503 /etc/haproxy/errors/503.http
errorfile 504 /etc/haproxy/errors/504.http
frontend http
bind *:80
acl msg-listing-read path_end -i /AAA/BBB/{user_id}
use_backend ppl-be-msg-listing-read-dev if msg-listing-read
backend ppl-be-msg-listing-read-dev
balance roundrobin
server ppl-msg-listing-read-dev localhost:8080 maxconn 32 check
listen stats
bind 0.0.0.0:81
stats enable
stats uri /
Any idea will be appreciated and Thanks in Advance.