How to reference UnityEngine.dll without strict HintPath?

I'm writing some external tool for my Unity project (localization files aggregator). I need UnityEngine.SystemLanguage. Consequently, I need to reference UnityEngine.dll. The problem is, a HintPath is needed to do it, which differs on different machines/environments. I can reference my Assembly-CSharp though (it is generated but have the same path and it's guid seems to be constant), but AFAIK there is no way to reference referenced assemblies. There is also pretty straightforward way to reference it I can see - just copy UnityEngine.dll from engine's files to solution folder (or use [NuGet package][1]). Does it differ between operating systems (so, would it work on Windows if I will take one from Linux editor)? [1]: https://www.nuget.org/packages/UnityEngine5/5.5.0