Redirection of URL without changing the host header

I've not tested this iRule but the idea is the re-write the host header on HTTP_REQUEST and re-write it back to the original value on HTTP_RESPONSE - resulting the client being unaware this has been changed.

You could also use a Stream expression in an iRule to do this.

when HTTP_REQUEST {
    set originalHost "[HTTP::host]"
    set newHost "ebc.mysite.com"
    if {[HTTP::uri] starts_with "/apple"} {
        node 193.13.14.5
        snat automap
        HTTP::header replace Host $newHost
        HTTP::uri / 
    }
}

when HTTP_RESPONSE {
    if {[HTTP::host] equals $newHost} {
        HTTP::header replace Host $originalHost
    }
}