Can a list of local multicast addresses be added to the channels list somewhere???

I thought it would be simple to just get the MAG 254 and set it up to decode an in house stream to check an encoder. With VLC I can go to rtp://224.2.2.2:1000 and see the streaming video. How do I do that with the MAG 254????? I am not having any luck figuring it out and the so-called manual is...