Can I create a test application that creates window handles greater than the 32 bit limit?

We have an automation utility that monitors and controls other applications. This utility was written years ago when 32 bits was the norm. Now that 64 bits is the norm, we have updated the code to not assume every window handle is 32 bits. Unit testing of the utility implemented a VB6 test app (32 bit) and we are upgrading the test app to C#.

The problem is that we occasionally encounter errors in the field where a window handle is greater than 32 bits and are still finding issues with our utility. While it is easy to fix the issues as they come up, it is hard to replicate the issues unless we load up a bunch of applications and hope we reach the address limit.

Is there a reliable way to create a Window that has a handle that is > 4G?