iRule HOST Header replace with dynamic content

This is an amended version, if there is only a first name (second field is "test1") then is will only add the first name. If not, it will add the first two fields to the new host header.

when HTTP_REQUEST {
    set field1 [getfield [HTTP::host] “.” 1] 
    set field2 [getfield [HTTP::host] “.” 2] 

    if {$field2 eq "test1"} {  
        HTTP::header replace "Host" ${hostField}.test2.mycompany.com 
    } else {
        HTTP::header replace "Host" ${field1}.${field2}.test2.mycompany.com
    } 
}