howto re-use DLL which has been written in VC ++

Hi everyone, I would like to re-use some functions from a DLL which has been written in VC++. I want to re-use it in C# envirenment. Does anyone know how to convert it? Please give me an example code written in C# to load the DLL and use functions. Can I use LoadLibrary() and GetProcAddress() functions like Visual C++ does? I will appriciate any ideas. Thanks.