im not sure if this'll work but you can try:
header("Location: www.blah1.com");
timeout(1500); //or whatever the function is named for delaying the php script.
header("Location: www.blah2.com");
That's one way to do it.
The other way is to direct it to the
www.blah1.com, put in a big delay value, and in index.php of
www.blah1.com, put another header("Location: www.blah2.com");