cable + HD converter + laptop


I currently receive digital TV via an RCN cable converter box connected to an analog TV.

For the sake of convenience, I want to replace the analog TV with a Dell laptop and upgrade to an HD converter box to view HDTV on the computer. (A converter box is required because RCN encrypts their signals even if the TV or computer is capable of receiving a high def)

I'm not sure this is even possible since the only inputs to the laptop are ethernet and usb. Is there anyway I can do this using an external usb HDTV tuner like those offered by Hauppauge or something like it? Hauppauge Computer Works : WinTV-HVR products

Thank you.