Referencing a 3rd Party assembly

Hi

I am trying to reference a 3rd party assembly in a .net core application on windows using visual studio 2015 (all components are installed). I cannot create a dotnet core application of any kind and add these 3rd party assemblies because it requires only .nuget packages specific for dotnet core.

I am trying to wrap these 3rd party assemblies in a nuget package - which I believe is the way to do it using a Portable Class Library.

I am not having any luck using the dotnet spec/pack or nuget spec/pack options to firstly create the packages with the included assemblies and secondly installing these packages on both a Windows or MacOS platform - How exactly is this done? and is it indeed possible to wrap full .net framework assemblies to be used on dotnet core platforms?

thanks

J