well if i remeber well,there's no hd input in beosystem2.
maybe you can think using a vga switch,buying a vga/hdmi adaptor,but it's quite a blasfemy...you should upgrade at beosystem 3!!this is the solution for hd inputs.i remember when i had the beosystem 2 that i did that(swith vga),linking a pc,so i could enjoy 1366x768 resolution in the beovision 4-50.