Embed VBA macro in VSTO Add-in

Question

I have a VSTO Add-in for Microsoft Word and I wish to embed a macro so it will be globally available from all VBA projects or other VSTO add-ins.

Is that possible? If so, how can it be done?

I hope it can be done without requiring Trust access to the VBA project object model (info) since I don't like having to ask my customers to do that.

I know that macros can be executed from VSTO like this

You define a function RunMacro

private void RunMacro(object oApp, object[] oRunArgs)
{
    oApp.GetType().InvokeMember("Run",
        System.Reflection.BindingFlags.Default |
        System.Reflection.BindingFlags.InvokeMethod,
        null, oApp, oRunArgs);
} 

and then call your macro like this:

RunMacro(oApp, new object[] {"NameOfMyMacro"}) 

or

RunMacro(oApp, new object[] {"NameOfMyMacro", "some", 3, "parameters"})

oApp is the Word.Application object, which I'm sure is available somewhere in a Word add-in.

It's also possible to execute the macro from VBA like this (Paraphrased)

Sub AppRun_AddIn_NoArg()
    Application.Run "ModuleName.MethodName1"
End Sub

And with arguments:

Sub AppRun_AddIn_WithArg()
    Application.Run "ModuleName.MethodName2", "ArgumentValue"
End Sub

The "embedded" macros I ask about here, should be executable in the same manner, for maximum compatibility with third parties.