First, you need to create a path of some sorts, whether it's an ellipse or a free-drawn path. Make sure that it doesn't have a stroke applied. Then use the Type on a Path tool (shift T), select on the path where you want the text to start and enter your copy, tweaking the path to get the angle you need.
In Illustrator, you have more control over how the type sits, how it's angled, flipped and so forth... so it might be a better choice if you've got Illustrator.
Or, if you've only got a few characters, you could skew each character on a straight path by a number of degrees to get the effect you want.