Is There A Keyboard Layout Creator for Android?
There is developer documentation found within the Android SDK that shows the basics of creating your own keyboard input method.

The actual sample of the touchscreen keyboard is part of the SDK sample, based off the documentation. Download the sample code, and look for the SoftKeyboard sources, there's a XML layout under the res/layout folder that represents the on-screen keyboard. 

All that aside, let's look at the question objectively, using a custom layout that was developed on the Windows platform, may not be easy to "translate" to the Android version, as there is strings attached, you do need the pre-requisite knowledge of Android SDK, Java in order to achieve a custom layout, unfortunately.

As per @geffcheng's comment above the OP's question containing the linky that pointed to the appropriate thread on XDA, the blog entry highlighting how to come up with your own version, is more or less the same as the official developer documentation. 

Other keyboard packages such as Swiftkey, Go Keyboard, SlideIT to name but a few, would have a feature to customize the layout appropriately using an add-on or third party to suit one's need, effectively tied to that keyboard. Using the SDK and documentation relating to the keyboard is the effective way to go about in rolling your own custom layout that is independent of Android version in use provided that the decision to support older versions is warranted. 

If the decision to focus on Android v4.x upwards, the actual app is on the Google Play Store, the source code to the AOSP keyboard is available to download and play with from here.