If I understood your question properly - you are trying to use your foxtel set top box hooked up to a TV capture card in your CORE and the CORE will be hidden.
You require an infrared sender (sometimes called IR blaster) which mimics the foxtel remote. These are typically wired IR LEDS that connect to some hardware on your serial port or USB.
No, this is not the same as an IrDA dongle and the dongle will not work.
You can either construct a homebrew serial port device for a few dollars and some soldering OR purchase one of the transeivers that work, such as USB_UIRT.
The IR wires will go to your foxtel box and get positioned directly in front of the infrared receiver so it will be as if you are holding a remote right up to the unit. All this can then be put away in a closet.