Custom Plug-in instrument with audiofile loading

I’m working on a custom plug-in instrument that allows to load an audiofile and then process that audio.

I think I have the basic idea down; I’ve created a plugin with 0 input buffers and a data parameter, that allows to drag & drop the audio file onto the plugin. But I don’t quite understand the next steps regarding the actual use of the audio; do I need to create a sound object? If so, how do I create an instance of System within a plugin? I’m having trouble putting the stuff from the docs and API reference together on this.

Some guidance would be much appreciated.

Thank you!

Edit:
Managed to get it working by writing the audio file to a buffer instead of using a sound object.