How do I use my internet modems ip address instead of my Wireless Routes ip address?

I have a website and I have set it up with my internet modems ip address and I recently hooked it up with my wireless router and it doesen't work as it is using a different ip address!!!!
Please help!

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).