iRule to redirect a variable to http

this is directly request.

[root@ve1023:Active] config  ssldump -Aed -nni 0.0 port 80
Feb 13 02:26:36 local/tmm notice tmm[4822]: 013e0001:5: Tcpdump starting bcast on :::0 from 127.1.1.1:34917
New TCP connection 1: 172.28.19.251(45151) <-> 172.28.19.79(80)
1329128801.9948 (0.0009)  C>S
---------------------------------------------------------------
HEAD /whatever HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: www.yahoo.com.acme.com.nz

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

this is request with f5 as an explicit proxy.

[root@ve1023:Active] config  ssldump -Aed -nni 0.0 port 80
Feb 13 02:27:30 local/tmm notice tmm[4822]: 013e0001:5: Tcpdump starting bcast on :::0 from 127.1.1.1:57671
New TCP connection 1: 172.28.19.251(45152) <-> 172.28.19.79(80)
1329128868.8840 (0.0012)  C>S
---------------------------------------------------------------
HEAD http://www.yahoo.com.acme.com.nz/whatever HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Host: www.yahoo.com.acme.com.nz
Pragma: no-cache
Accept: */*
Proxy-Connection: Keep-Alive

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

this is an example irule when using f5 as an explicit proxy.

[root@ve1023:Active] config  b virtual bar list
virtual bar {
   destination 172.28.19.79:80
   ip protocol 6
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@ve1023:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
   set host [string tolower [HTTP::host]]
   set proxy_uri [string tolower [HTTP::uri]]
   set uri [getfield $proxy_uri $host 2]
   set newhost [string map {".acme.com.nz" ""} $host]

   if {$host ne $newhost} {
      HTTP::redirect "http://$newhost$uri"
   }
}
}

[root@ve1023:Active] config  curl -I http://www.yahoo.com.acme.com.nz/whatever -x 172.28.19.79:80
HTTP/1.0 302 Found
Location: http://www.yahoo.com/whatever
Server: BigIP
Connection: Keep-Alive
Content-Length: 0