There is as far as I know, no way to do denies using a mask in the .htaccess file so the only block would be for a full subnet like
So to only block those 100, you will have to put them one on a line or in groups like...
deny from 192.168.100.122 192.168.100.123 192.168.100.124 ...
If you are using Linux or some firewall on your box, you could block access that way too.
If it is a particular page, you could add some php code to check the ip and forward to another page if you don't like the value too.