As far as I am aware, yes. Using "cgo" (by importing "C") you can include C header files, and all c source files are compiled together with the Go files in your package. So if you have a foo.c containing int foo(int) you can just call it from Go by
Either way if you're going to build UI for Windows C#/QT with an C FFI is the more sane way to go. Back when I worked on game engines most of the time we had the fast code down in native and used C# for the tools since it's such a productive framework compared to win32.
i := C.foo(C.int(j))
Assuming j is a Go int type.