VBAでC#のdllを使うサンプル

VBASampleAddin.cs

using System;
using System.Text;
using System.ComponentModel;
using System.Runtime.InteropServices;

namespace VBA_SampleAddin
{
    [ComVisible(true)]
    public interface IVBA_Addin
    {
        [Description("HelloWorldを出力します。")]
        string HelloWorld(string name);
    }

    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.None)]
    public class VBA_Addin : IVBA_Addin
    {
        /// <summary>
        /// HelloWorld
        /// </summary>
        public string HelloWorld(string name)
        {
            string msg = "Hello World! " + name;
            return msg;
        }
    }
}