Welcome, its always nice seeing a fellow African joining the Forum.
Firstly, what you need is an analogue TV-Card with a Hardware Mpeg2 decoder. The "Hauppauge PVR150" is very popular and well supported by MediaPortal. There are a number of newer and better TV-cards, but they usually have more challenges to get them working. Also if you are planning on using the Hauppauge card with a big-screen TV, I would recommend you also buy a good graphics-card that will improve the image quality.
Secondly, you would have to buy a remote-control (like the Microsoft MCE Remote) that has remote-blasters that can change the channels on the DSTV-decoder for you. To make the remote blasters work, you will have to install the "MCE Replacement Plugin" or the "IR Server Suite" and teach it your DSTV-Remote commands.
Thirdly, you will have to import an "Electronic Program Guide" using an XMLTV-file. If you have the same channels and schedules as we do in South Africa, then you can download the XMLTV-Guide from the following web-site,
XMLTV - DSTV Virgingirl’s Weblog , otherwise you will have to see if you cant find one for Uganda somewhere on the internet.
Hope this helps....