Hey grb1212, this does seem to be requested a far amount so let me help you out a bit here.
First, you will need to install Visual Studio, I recommend 2017 Community edition. Be sure to follow the documentation with regards to the pre-requisites
Next, you will want to create a "C++ Plugin" template from the CRYENGINE Launcher.
Follow the documentation regarding generating a solution
and compiling and running the template project. If all goes well, you can modify the code like so;
Now after compiling and opening the project in the Sandbox editor, you can test it with something like;
Let us know if you get stuck or need any help with this. As mentioned though, this is generally not something we would encourage. This is provided as a naive example of the most basic method of combining Flow Graph and Schematyc and should not be used for production. Please let us know what you would like to be implemented in Schematyc