It's a better idea to use sub*domains* for this, just create another A-record for the subdomain and then you're done.
If you want to use the sub-directories still, you have two options:
mod_rewrite to write a subdomain to a directory, where you'd create
sub2.example.com and it would be accessible via
My recommended approach, however, is to use the
mod_proxy (Make sure all of the mod_proxy* modules are enabled).
#you can have servers running on any port
Allow from all