iRule to take host information from absoluteURI and re-write the host header

e.g.

// config

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.24.10:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        qux
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vs-index 60
}
root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:80 {
            address 200.200.200.101
        }
    }
}
root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm rule qux
ltm rule qux {
    when HTTP_REQUEST {
  set host_in_uri [getfield [HTTP::uri] / 3]
  if { [HTTP::host] ne $host_in_uri } {
    HTTP::header replace Host $host_in_uri
  }
}
}

// test

[root@ve11a:Active:In Sync] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.24.1(53936) <-> 172.28.24.10(80)
1407713054.1000 (0.0019)  C>S
---------------------------------------------------------------
GET https://client1.test.com/path/query?test=A HTTP/1.1
Host: proxy.domain.net
X-Forwarder-host: proxy.domain.net


---------------------------------------------------------------

1    1407713054.1000 (0.0000)  C>S  TCP FIN
New TCP connection 2: 200.200.200.14(53936) <-> 200.200.200.101(80)
1407713054.2039 (0.1035)  C>S
---------------------------------------------------------------
GET https://client1.test.com/path/query?test=A HTTP/1.1
Host: client1.test.com
X-Forwarder-host: proxy.domain.net

---------------------------------------------------------------