Extend distZip/distTar

I’m trying to generate multiple zip files for my project using the application plugin so that I can include OS specific exe files in the zip.
I have the exe files under src/win32/dist and they end up in the win32 zip file fine, but that’s all that’s in that zip file.

How do I configure my additional distributions so they each include everything in the main zip PLUS these exe files, not just these exe files?

Here’s an example bit of config:

distributions {
    //I want win32 to include the same as the 'main' dist 
    //plus files in src/win32/dist
    win32 { 
        contents {
            from { libsDir }
        }
    }
}

Here’s the directory structure:

src/
    win32/
        dist/
            prunsrv.exe        <-- win32 specific exe
    amd64/
        dist/
            prunsrv.exe        <-- amd64 specific exe

I got the answer over on stackoverflow:

win32 { 
    contents {
        with project.distributions.main.getContents()
    }
}