I’ve made a small update to MockItNow to allow you to throw exceptions when replaying function calls. You basically record the function call as normal, and provide the exception object that you want to throw during the replay using the EXPECT_THROW macro. You can also make a function default to throwing an exception at registration time using REGISTER_THROW.
If you want to see a couple of examples of this feature, take a look at the bottom of the sample file here.