Yes it would replace your macro. If you've ever seen those adapters that allow you to attach your DSLR to a telescope...it's the same concept. Attach the adapter ring to the camera body, then attach the mesoscope. (not that I've ever actually seen a mesoscope firsthand, but I can't imagine any other way it would work)
The one disadvantage of using a tool like this is that depending on your camera model, you may end up losing features like light metering and (obviously) your autofocus. I know with my D80 if I use older Nikon F-mount lenses they will match up to the camera body, but I have to measure exposure using 1 of 2 methods: trial and error, or an external light meter. Some of the newer models do allow you to have light metering no matter what lens is connected to the body...I don't know enough about your camera to say whether or not that'd be the case.
