FQDN resolution and used in load balancing

Hello, I am working on requirement where I need to load balance traffic on FQDN. The FQDN is passed to F5 in HTTP header (Header name: backend-server). I have put iRule as below which is working fine.

when HTTP_REQUEST {

set lb_server [HTTP::header "backend-server"]
set lb_port [HTTP::header "backend-port"]
HTTP::header replace "Host" "$lb_server"
set dest [lindex [RESOLV::lookup @8.8.8.8 -a "$lb_server"] 0]
node $dest $lb_port

}

I would like to extend this further if FQDN is resolving in multiple IPs, use those IPs to load balance in round-robin or least connected fashion.

Would anyone know how this can be done? Any idea/suggestions?

Thank you.