What is the correct way of temporarily changing a thread's preferred UI language?

A customer ran into a crashing bug in their shell extension. The shell extension wants to change the thread's preferred UI language temporarily, so that it can load its resources from a specific language. You'd think this would be easy: // error checking elided for simplicity// There is a bug in this code - read on// Get the current thread preferred UI languagesULONG cLanguages;PZZWSTR