Traffic routing with iRules

When you say "subdomain", are you referring to subdomains of example.com? (ex. email.example.com, www.example.com, testwww.example.com, etc.)? Can I also assume that the URIs (/supra, /seo, /staff, and /marketing) exist for all applications? If so, then something like this perhaps:

when HTTP_REQUEST {
     set hostlist [list email.example.com www.example.com test.example.com test1.example.com]

     if { [string tolower [HTTP::host]] equals "testwww.example.com" } {
          pool $HTTP_pool
     } elseif { [lsearch $hostlist [string tolower [HTTP::host]]] ne -1 } {
          switch -glob [string tolower [HTTP::uri]] {
               ...
          }
     }
}