Here is a toy model for news shocks. There is a bug somewhere since I’m not able to recover the true moments on the shock one period ahead but it seems to do well for the other parameters. Anyway, this is just a toy to tinker with. Let me know if you make any interesting-fun modifications or if you happen to find the bug 
Cheers
ToyGen.xls (31 KB)
Toy1_v1.mod (1.06 KB)