neighbor 82.219.123.221 {
    [....] 
    flow {
       route {
          match {
             source 10.0.0.1/32;
             destination 192.168.0.1/32;
             port =80;
             destination-port =3128 >8080&<8088;
             source-port >1024;
             protocol tcp;
          }
          then {
             discard;
          }
       }
    }
 }

 thomas@router> show configuration protocols bgp 
 local-as 30740;
 group flow {
    type external;
    multihop;
    local-preference 100;
    local-address 82.219.123.221;
    import no-export;
    export deny-all;
    peer-as 65500;
    neighbor 82.219.131.242 {
       traceoptions {
          file bgp;
          flag all;
       }
       family inet {
          unicast;
          flow {
             no-validate everything;
          }
       }
       family inet6 {
          unicast;
       }
    }
 }

 thomas@router> show configuration policy-options policy-statement everything       
 then accept;

 thomas@router> show route table inetflow.0 extensive 
 
 inetflow.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
 192.168.0.1,10.0.0.1,proto=6,port=80,dstport=3128,>8080&<8088,srcport>1024/256 (1 entry, 0 announced)
   *BGP    Preference: 170/-101
           Next hop type: Fictitious
           Next-hop reference count: 1
           State: <Active Ext>
           Peer AS: 65500
           Age: 1:13 
           Task: BGP_65500_30740.82.219.131.242+32319
           AS path: 65500 I
           Communities: no-export traffic-rate:0:0
           Localpref: 100
           Router ID: 82.219.131.242