1. With a home router, there's generally Network Address Translation (NAT) function built in which permits all of the computers on your private network to share "one" IP address provided by the Internet Service Provider (ISP). So I guess I don't understand why you need "additional" IP addresses.
Also, I'm not sure what the "range expander" has to do with additional IP addresses (but I've never used one, so maybe I'm missing something...).
2. How many private addresses are you currently using?
3. Are you trying to add "additional" IP addresses provided by the ISP to your network so you have multiple "public" addresses?