References to a Forms Project?

I have a 3rd party dll, which I actually makes more sense for me to use from the Forms project than the plattform-depended projects.
However, I don't see a "reference" section in the Forms project.
The only way around this, is to wrap the dll with my own api and interfaces and and pass the concrete implementations from the platform-specific projects to the form instance when the application initializes.

Is there a better way ?
thanks,
Erez