Yes you can, its a wonderful highway road you will enjoy the entire ride (Shimla-Nahan-Dehradun-Musoorie). In between you can visit Gurudwara at Pontasahib. In Musoorie I would suggest you to go to Landour or Laltibba if you are seeking for peace. And Don't forget to eat famous Omelette of Lovely Omelette at Musoorie.