Office Addins

Hi
I´m writting a Com addin for office 2000.
Because there isn´t enought documentation
for vc++ i had to solve myself lots of problems,
but i can´t solve this, please read.

Office Shapes has the OnAction Property to execute a macros when i click on it.

In VB works in that way;

OnAction = "DoSomething"

private sub DoSomething()

end sub

I´m working with a Com Add-In wrote in VC++
but i don´t know how to do the same thing in VC++.
I can´t use CComQIPtr types because i can´t see the
OnAction property.

Using invoke i can set the OnAction Property but
what kind of string should i pass to tell OnAction that
i want to execute a VC++ class member function when the shape is clicked ???

Thanks