First, welcome to the board
You can 'get' more channels (at 28.2°E), but, your choice is limited both at 28.2°E (SKY) and because you have a Digibox.
Check here and see what's new to you
Lyngsat
Otherwise its a fiddly-faff and you must be able to move your dish to other satellites. Knowledge of dish positioning is a must; else you might get into a big heap of trouble (scratch a mark/draw an idellible line on the pole thing and dish bracket so you know where you started).
The first place to head is Astra 19°E (about 5mins clockwise) and then, later, Hotbird at 13°E. With a standard dish you'll get most of their offerings. When you get there, most will be (sic) foreign channels.
Finally, you will be limited to symbol rates of 27.5Mbaud and 22Mbaud - H or V and you'll have to input them manually (and tediously) into your digibox (ADD CHANNELS menu). When you are positioning the dish you should be watching for the signal in the SERVICES > SYSTEM > SIGNAL TEST menu.
Use the above site to check-out available frequencies.
Have Fun and hope it helps,
Mark.