Can't access OWA Externally

Hello all.  Here is the situation.  Everything worked fine until Comcast replaced our modem, so I think it has something to do with that, but not sure.  We have three servers each with local IPs of 10.0.0.2, 10.0.0.3, and 10.0.0.5.  Exchange server is on the 10.0.0.2 server.  Internally, I can type 127.0.0.1/exchange and get it to work, but when I type in our Static IP, Google comes back with a broken link error.  the funny thing is with the old modem, if i just typed in our static IP by itself externally, it couldn't find anything, but now I get the login of the modem.

Comcast keeps wanting me to change the modem IP settings, but when I do, the only way to get to the internet is to change the IPs on my servers, which worked fine before as the 10.0.0.*.  So, I still think there is something in the modem that is needing configuration.  Comcast mentioned something about passthrough, and tried that, but to no prevail.  I tried port forwarding port 80 and 443 even though we don't have a certificate to the exchange server, and nada.  

I hope this makes sense.

Mike