HAPROXY redirect subfolder

Dear All,

I have my website like https://myserver.mydomain.com when a user reach the root url, i want to be redirected to https://myserver.mydomain.com/mysite each time i suggest i can do with redirect 301 but is not working ! someone are an idea ? all traffic are https and my haproxy resume 25 subdomain like https://server1.mydomain.com https://server2.mydomain.com

Helo are Welcome