Static route for entire octet or by host name?
You can "wildcard" IP addresses by just changing the netmask:
route add 192.0.2.0 mask 255.255.255.0 <router>
There's no way to route to a hostname, because names are handled at a higher level of the network stack.
It sounds like you're trying to solve a problem that you are having in a different manner than you really should. What problem are you actually trying to solve? routes have nothing do with names, you can't really mix the two. The names are looked up at the time the route is entered and translated to an IP address at that time.