Register DLL from C#

RegisterDLL

public class Registrar : IDisposable
{
    private IntPtr hLib;
 
    [DllImport("kernel32.dll", CharSet = CharSet.Ansi, ExactSpelling = true, SetLastError = true)]
    internal static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
 
    [DllImport("kernel32.dll", SetLastError = true)]
    internal static extern IntPtr LoadLibrary(string lpFileName);
 
    [DllImport("kernel32.dll", SetLastError = true)]
    internal static extern bool FreeLibrary(IntPtr hModule);
 
    internal delegate int PointerToMethodInvoker();
 
    public Registrar(string filePath) 
    {
        hLib = LoadLibrary(filePath);
        if (IntPtr.Zero == hLib)
        {
            int errno = Marshal.GetLastWin32Error();
            throw new Win32Exception(errno, "Failed to load library.");
        }
    }
 
    public void RegisterComDLL()
    {
        CallPointerMethod("DllRegisterServer");
    }
 
    public void UnRegisterComDLL()
    {
        CallPointerMethod("DllUnregisterServer");
    }
 
    private void CallPointerMethod(string methodName)
    {
        IntPtr dllEntryPoint = GetProcAddress(hLib, methodName);
        if (IntPtr.Zero == dllEntryPoint)
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());
        }
        PointerToMethodInvoker drs = 
               (PointerToMethodInvoker) Marshal.GetDelegateForFunctionPointer(dllEntryPoint, 
                           typeof(PointerToMethodInvoker));
        drs();
    }
 
    public void Dispose()
    {
      if (IntPtr.Zero != hLib)
      {
          UnRegisterComDLL();
          FreeLibrary(hLib);
          hLib = IntPtr.Zero;
      }
    }
}


//
// How to Use
//
using (Registrar registrar = new Registrar("path\\to\\com.dll"))
{
    registrar.RegisterComDLL();
    return base.Execute();
}