how does port forwarding work with xfinity

Needing assistance with port forwarding. I have a machine on my local network. I have given it a static ip. If I type this ip into a browser from  computer using my network I get my welcome page.

I wish to use port forwarding to access this welcome page from the external web using my public ip. If I put my public ip into a browser it takes me to the admin gateway tool page which is the same as the default gateway 10.0.0.1

How do I configure my portforwarding to access the welcome page on my local server from the external web? Cant seem to get this to work with infinity. 

thanks