Time Capsule from Internet

Greetings,

Through many unsuccessful trials of reading different posts and guides - I still am scratching my head as to accessing my Time Capsule away from home, across the internet. Any help is GREATLY appreciated!

So my current home network is set-up as such:
internet> qwest modem> Buffalo Router (creating a wireless network)> Time Capsule - from LAN of Buffalo router to WAN port of TC (creating yet another wireless network.)

I have followed guides like this one:
http://guides.macrumors.com/Using_R...treme_Base_Station_with_Shared_USB_Hard_Drive
...... and have had no luck.
I know it complicates things being that the internet goes through the router and not the Time Capsule first, but when I connect the TC directly through the WAN port from the modem (bypassing the Buffalo router completely) - I still run into the same problem - a screen saying "Error - server does not exist or is not available at this time."

I have tried forwarding TCP ports 548 through the Buffalo router and the modem, with the little knowledge I have I can't be sure I did it right.

Any ideas?? Thanks!!