Using your receiver for a fixed dish setup, on 28.2E, is a bit of a waste, but it's very easy to do.
Go into the menu, Service searching, and select tuner A, or B, depending where you have connected your coax cable.
Set the configuration mode to simple, using the left/right arrow buttons, then set the Mode option to Single, and satellite to Astra 2, 28.2E.
Once done exit, and use the System Searching, and scanning option, to scan in your channels, Automatic, to let it scan all of them in itself, or manually to add the channels you want.