Hi Andrew,
I have just published an article called
Finding analogue TV broadcast frequencies for MCE 2005.Perhaps this can help you find your missing SABC channel.
Regarding your question, with your official MCE remote comes with the remote control, a USB reciever and 2 remote blasters that plug into the reciever.
You can use one of the remote blasters to control other devices such as a DSTV decoder or other set top boxes.
You
then setup MCE to use a set top box and it will step you through the
process to get it setup so that MCE will change the channel on your
DSTV decoder when it is required.