Tobii Communicator should be able to learn and play out DirecTV Infrared (IR) remote controls. If it does not - the DirecTV satellite box may have its remote control set to send out Radio Frequency (RF) signals.
There is an option to change the remote control from sending RF to IR. This is done in the Settings on the DirecTV box. Contract DirecTV support for instructions for this as they send out different boxes and would be the best resource for instructions how to switch the setting on your specific box. Once this is done, continue with the same steps to setup, learn, and use the remote in TC4.