Can I scald milk in the microwave?
Yes, you can. Adjust the power to medium-high, pour the milk into a Pyrex measuring cup (or similar), and drop a wooden implement (a disposable chopstick is ideal) into the cup.

Keeping the heat lower than maximum will give you more time to react when the milk threatens to boil over. The chopstick will prevent the rare but possible occurrence of superheating.

Or, you can just do it in any microwave-safe container, throwing caution to the wind. To scald milk, you want to bring it to just below the boiling point (82C, 180F). Watch it carefully, milk loves to go from still to boiling over in a nanosecond. When it first starts to bubble, it's done. 

The microwave is actually an excellent way to scald milk. It is much easier to burn it on the stove.