I need to redirect backend to ip server with a context

Hi i have this problem:

I need to redirect my backend server, using a particular context after ip and port definition…

Follow my example.

frontend my-https

bind *:443 ssl crt /mypath/haproxy/mycer.pem
log-format “%ci:%cp [%t] %ft %b/%s %Tw/%Tc/%Tt %B %ts %ac/%fc/%bc/%sc/%rc %sq/%bq %[var(xxxxxxxxxxxx)]”

    use_backend bk_1 if { path_beg /pippo }

backend bk_1
balance roundrobin
server s1 xxx.xxx.xxx.xxx:3101/services ssl ca-file /etc/haproxy/cer.pem check weight 99
server s2 xxx.xxx.xxx.xxy:3101/services ssl ca-file /etc/haproxy/cer.pem check weight 01

How can i solve it?

Thanks

Solved using:

http-request
set-path /path/subpath

In backend definition