Complex sentence: Radio host Fiorello in his show on Radio Due created a character named "lo smemorato di Cologno": the voice was an imitation of Silvio Berlusconi (Cologno being the headquarter of his TV channels).
Split into simpler sentences: Radio host Fiorello created a character named "lo smemorato di Cologno" on his show on Radio Due. The voice was an imitation of Silvio Berlusconi (Cologno being the headquarter of his TV channels).