iRule URL Rewrite for Multiple domains

when HTTP_REQUEST {
  if { [HTTP::uri] contains "select"  } {
    use pool web_pool_web02
  } elseif { [HTTP::uri] contains "survey"  } {
    use pool web_pool_web02
  } elseif { [HTTP::uri] contains "bcaonline"  } {
    use pool web_pool_web01
  } elseif { [HTTP::uri] contains "onlinene"  } {
    use pool web_pool_web02
  } elseif { [HTTP::uri] contains "onlinesubscadmin"  } {
    use pool web_pool_web02
  } elseif { [HTTP::uri] contains "MAILFORM"  } {
    use pool cms_saiglobal
  } elseif { [HTTP::host] contains "saiglobal.com.au"  } {
    HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } elseif { ([HTTP::host] contains "sai-global.com.au") and ([HTTP::uri] contains "shop") } {
    HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } elseif { [HTTP::host] contains "saiglobalinc.com"  } {
    [HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } elseif { [HTTP::host] contains "qas.com.au"  } {
    HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } elseif { ([HTTP::host] contains "www.standards.com.au") and ([HTTP::uri] contains "catalogue") } {
    HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } elseif { ([HTTP::host] contains "cqc-sai.com") and ([HTTP::uri] contains "shop") } {
    HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } elseif  { ([HTTP::host] contains "sai-global.com") and ([HTTP::uri] contains "shop") }  {
    HTTP::redirect "http://www.saiglobal.com/[HTTP::uri]"
  } else {
    use pool web_pool_shop
  }
}

The first few lines at the top do some load balancing to different pools.

I then have some detections which descriminates redirects if the traffic is on specific uri eg. if the directory path is /shop and the domain name is bla bla then redirect. This has been necessary as we have a cms that handles a lot of virtual sites /directories within IIS. however, if I simply do a find and replace (something the irule editor doesn't have)

find

replace

the irule says that the rule is valid, but my sites start failing.