Create <Host/> like:
<Host name="localhost">
<Alias>xxxxx.xxxx.xx</Alias>
<Alias>yyyyy.xxxx.xx</Alias>
<Alias>yyyy1.xxxx.xx</Alias>
Start AS and httpd will complain:
[Wed Jan 06 16:15:39 2010] [debug] mod_manager.c(2053): manager_handler ENABLE-APP processing: "JVMRoute=jfcpc&Alias=localhost,xxxxx.xxxx.xx,yyyyy.xxxx.xx,yyyy1.xxxx.xx&Context=%2fsslapp"
[Wed Jan 06 16:15:39 2010] [debug] mod_manager.c(1743): manager_handler ENABLE-APP error: MEM: Can't read host alias