Forwarding any query based on servername Except for one to a specific port

Hi,
I have to use haproxy on my host ( listening port 80 ) .
I have an apache server ( port 81 ) , which serves several websites based on servername.
I have another application ( a chabot : botpress ) whi runs on port 3005.

I tried the following but I guess I’m missing something :
*> *
> global
> log 127.0.0.1 local0 debug
> log 127.0.0.1 local1 notice
> maxconn 4096
> user haproxy
> group haproxy
> daemon
*> *
> defaults
> log global
> mode http
> option httplog
> option dontlognull
> retries 3
> option redispatch
> timeout connect 10000
> timeout client 60000
> timeout server 60000
> maxconn 2000
*> *
> frontend localnodes
*> bind :80
> mode http
> default_backend nodes
*> *
> backend nodes
> mode http
> balance roundrobin
> option forwardfor
> http-send-name-header Host
> server www.mydomain.com www.mydomain.com:81
> server support.mydomain.com support.mydomain.com:81
> server chatbot.mydocmain.Com 192.168.1.35:4000

Any insight on what I’m doing wrong ?