Need urgent Redirect help!!!!

Well now you're talking about two separate iRules, on two separate Virtual Servers.

On the port 80 virtual server you'd have the simple rule that you posted above:

when HTTP_REQUEST {
  HTTP::redirect https://[HTTP::host][HTTP::uri]
}

Then you'd have another virtual server set up with the same IP address listening on port 443. That virtual server would then have an iRule assigned to it that would check to see if the URI started with site[1-4] and send them to the appropriate pool if that was the case.

Something like:

when HTTP_REQUEST {
  switch -glob [string tolower [HTTP::uri]] {
    "/site1*" -
    "/site2*" -
    "/site3*" -
    "/site4*" {
      pool www_apache
    }
  }
}

Keep in mind that the Virtual Server listening on 443 will have to have a client SSL profile configured as well so that it can decrypt the traffic at the BIG-IP, otherwise it won't be able to read the URI to route appropriately.

HTH,

Colin