the plugin loader gives me the errorString "Can not find the specified module"
it is probable that you are dealing with at least two different problems.
To simplify things do the following:
1. Create an "empty" plugin which does not have external dependencies (not linking to libvlc), and have it load successfully in your application.
2. Once you know that your plugin setup is correct and working, add the specific code you need it to perform, and the additional dependencies (libvlc).
Don't forget, that your plugin will always will have to be able to link to libvlc and know where it libvlc is, unless you build your plugin statically against libvlc.