host header redirect (?) and hide URI

I get file not found.

 

I can request www.outdoor.somedomain.com/trees from my browser, and I can redirect to it using:

 

when HTTP_REQUEST {

 

if { ([HTTP::host] starts_with "www.trees.somedomain.com")} {

 

HTTP::redirect "http://www.outdoor.somedomain.com/trees"

 

}

 

}

 

But this doesn't work:

 

when HTTP_REQUEST {

 

if {[string tolower [HTTP::header "Host"]] eq "www.trees.somedomain.com"}{

 

HTTP::header replace "Host" "www.outdoor.somedomain.com"

 

HTTP::uri "/trees"

 

}

 

}

 

I just get a 404 file not found error