HTTP Redirect based on protocol

The simplest way would be to test the port on which the request is received, and set the protocol string based on that.

when HTTP_REQUEST {
  if {[string tolower [HTTP::host]] contains ".com"}{
    set host [string map -nocase {.com .net} [HTTP::host]]
    if {[TCP::local_port] == 443 {
      set proto "https"
    } else {
      set proto "http"
    }
    HTTP::redirect "$proto://$host[HTTP::uri]"
  }
}

(Since you mentioned you want this to work on multiple VS, I took the liberty of also adding a string map function to re-write any .com hostname to .net, which you can of course adjust to match your specific requirements.)

HTH

/deb