Set up IP range & ports

Hi -

I have a MR2100 and need to open a specific range of ports in order to use for a HICAPS device (EFTPOS-like terminal for processing insurance claims in Australia).

The range of IP addresses I need to use is:

However, when in the router settings (accessed by logging into routerlogin.net, I only have the option to set up Port Forwarding, and only one IP address at a time.

How should I be setting it up to enable access?

Thanks in advance.