1.I'm right outside of your door.Come out after you finish your stuff.
2.I am standing in front your building.You can see me if you look down through the window.
3.She is going to the train station tomorrow,are you going to send her off?
4.I will have a business trip to Beijing tomorrow morning by train.
你说的go to beijing on business中的on 并不太准确,不建议使用.我个人觉得改进的方法是变on为for.