callback vb6 application in .net domain

there is a old VB6 project in our company. we add some new feature that is COM component be writed by C# recently.
the VB6 application calling the COM component do some work like open a window dialogs or display some client information. for some special reason now we need to calling some vb6 method in C# component, how to do it?

finally,i find some very cool code. source code download from http://www.1try.com.cn/upload/testeventwvb.zip