This could require more than just fixing the template for cocoplugin.cmake.

The cocoplugin.cmake I have generated with my Qt Creator 17.0 writes:

if(CMAKE_HOST_APPLE)
    set(wrapperdir "${cocopath}/")
elseif(CMAKE_HOST_UNIX)
    set(wrapperdir "${cocopath}/bin/")
elseif(MINGW)
    set(wrapperdir "${cocopath}\\bin\\")
else()
    set(wrapperdir "${cocopath}\\" )
endif() 

However, with Coco 7.2.1, there's no such folder as ${cocopath}/bin. 
*Though there's ${cocopath}/MinGW in this version, which doesn't exist in the latest 7.3.0.

This is also the case for Coco 7.3.0.
This seems to cause a trouble when cmake configuration and generation is done with MinGW, because it looks into ${cocopath}/bin for coco wrappers, which don't exist.