A host ExcelDna add-in loading and unloading another add-in

Sample Add-In

<DnaLibrary Name="Sample Add-In" Language="CS" RuntimeVersion="v4.0">
<Reference AssemblyPath="System.Windows.Forms.dll"/>
<Reference Name="Microsoft.Office.Interop.Excel" />
<![CDATA[
using System;
using ExcelDna.Integration;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;

public class MyAddIn : IExcelAddIn
{

	public void AutoOpen()
	{
		Excel.Application XL = (Excel.Application)ExcelDnaUtil.Application;
		XL.OnKey("^p", "Macro_Test");

		MessageBox.Show("Add-In Loaded.", "Add-In AutoOpen"); 
	}

		
	public void AutoClose()
	{

	}

	public static void Macro_Test()
        {
		MessageBox.Show("Macro Test", "Macro Test"); 
	}

}
]]>
</DnaLibrary>