Add the plugin developed in VS 2008 to the VS 2003 IDE

Question

Hi,

I have created a visual studio plugin using Visual Studio 2008 and C#. I was sucessful in adding this plugin to the VS IDE 2008. The steps that I followe was .....
1) Create a folder named Addin ina dir or a folder.
2) Add the .Addin file to the Addin folder.
3) Modify the .Addin file.... Edit the assembly tag with the path where the .dll file of the plugin is kept.
4) make a registry entry in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\AutomationOptions\LookInFolders . Under the LookInFolders make a string value entry. this entry will be the path of the Addin folder where your .addin file is kept. Don't provide any value to it.
5) When you'll open the VS 2008 the plugin will be reflected.

My problem statement is I want to add the same plugin in Visual Studio 2003 IDE. But I am not finding any way or registry entries where I can add this plugin path.

A quick help will be appriciated.

Thanks In Advance.