I have an Outlook 2007 installed on.
I have small Outlook Add-in example (in C++) somewhere from
http://www.codeproject.com ..

I try to catch buttons, located at 'Appointment window toolbar' (in Outlook
Calendar press some date, and this window will be appear) press by the
following way:

Function OnInspectorEvent is called when new inspector being created:

CAdding private member
CTimeZonesButtonCatcher m_watch

void __stdcall CAddin::OnInspectorEvent (LPDISPATCH ctrl)
{
OutlookInspectorPtr insp(ctrl);
OutlookCommandBarsPtr bars;
HRESULT hr = insp-get_CommandBars(&bars);
m_watch.FindTimeZonesButton(bars);
m_watch.SubscribeToItemEvents();
MessageBox(NULL, "Inspector event hooked !!", "!", MB_OK | MB_APPLMODAL);
}

There is CTimeZonesButtonCatcher class:
header:
//////////////----------------------------------------------
-------------------------------///////////////////////////// /
// TimeZonesButtonCatcher.h

#pragma once

class CTimeZonesButtonCatcher :
public IDispEventSimpleImpl4, CTimeZonesButtonCatcher,
&__uuidof(Office::_CommandBarButtonEvents)
{
public:
CTimeZonesButtonCatcher()
{
}

// event sinks map
BEGIN_SINK_MAP(CTimeZonesButtonCatcher)
SINK_ENTRY_INFO(4, __uuidof(Office::_CommandBarButtonEvents), 0x00000001,
OnClick, &CancelableDispEventHandler)
END_SINK_MAP()

public:
// Handles item events
HRESULT(SubscribeToItemEvents)();
HRESULT(UnSubscribeToItemEvents)();
bool FindTimeZonesButton(OutlookCommandBarsPtr& bars);

protected:

virtual void __stdcall OnClick(LPDISPATCH ctrl, VARIANT_BOOL * cancel);

private:

template typename CONTAINTER_CLASS
OutlookCommandBarControlPtr FindControl(CONTAINTER_CLASS parent, CComBSTR
caption);

OutlookCommandBarControlPtr TimeZoneButton_m;
};

realization:
//////////////----------------------------------------------
-------------------------------///////////////////////////// /
// TimeZonesButtonCatcher.cpp : implementation of CTimeZonesButtonCatcher

#include "stdafx.h"
#include "TimeZonesButtonCatcher.h"


HRESULT CTimeZonesButtonCatcher::SubscribeToItemEvents()
{
HRESULT hr = IDispEventSimpleImpl4, CTimeZonesButtonCatcher,
&__uuidof(Office::_CommandBarButtonEvents):ispE ventAdvise(TimeZoneButton_m, &__uuidof(Office::_CommandBarButtonEvents));
return hr;
}

HRESULT CTimeZonesButtonCatcher::UnSubscribeToItemEvents()
{
HRESULT hr = IDispEventSimpleImpl4, CTimeZonesButtonCatcher,
&__uuidof(Office::_CommandBarButtonEvents):ispE ventUnadvise(TimeZoneButton_m);
return hr;
}

bool CTimeZonesButtonCatcher::FindTimeZonesButton(Outlo okCommandB arsPtr&
bars)
{
if (!bars.p) return false;

// Look for menu bar
int count;
bars-get_Count(&count);

for (int i=1; i=count; i++)
{
VARIANT index;
index.lVal = i;
index.vt = VT_I4;
OutlookCommandBarPtr bar;
HRESULT hr = bars-get_Item(index, &bar);
CComBSTR barName;
bar-get_Name(&barName);
if(barName == _T("Standard") )
{
OutlookCommandBarControlPtr item = FindControl(bar, _T("I&nvite Attendees") );
if(item.p == NULL)
{
return S_FALSE;
}
TimeZoneButton_m = item;
break;
}
}

if (!TimeZoneButton_m) return S_FALSE;

}


template typename CONTAINTER_CLASS
OutlookCommandBarControlPtr
CTimeZonesButtonCatcher::FindControl(CONTAINTER_CL ASS parent, CComBSTR
caption)
{
OutlookCommandBarControlsPtr controls;
HRESULT hr = parent-get_Controls(&controls);
int controlsCount;
hr = controls-get_Count(&controlsCount);
for(int i=1; i=controlsCount; i++)
{
VARIANT controlsIndex;
controlsIndex.lVal = i;
controlsIndex.vt = VT_I4;
OutlookCommandBarControlPtr control;
hr = controls-get_Item(controlsIndex, &control);
CComBSTR controlName;
hr = control-get_Caption(&controlName);
if(controlName == caption)
return control;
}
return OutlookCommandBarControlPtr();
}

void __stdcall CTimeZonesButtonCatcher::OnClick(LPDISPATCH ctrl,
VARIANT_BOOL * cancel)
{
OutlookCommandBarButtonPtr button(ctrl);
MessageBox(NULL, "Hi2222", "Catched !", MB_OK | MB_APPLMODAL);
}
//////////////----------------------------------------------
-------------------------------///////////////////////////// /

line in stdafx.cpp:
_ATL_FUNC_INFO CancelableDispEventHandler = {CC_STDCALL, VT_EMPTY, 2,
{VT_DISPATCH, VT_BYREF | VT_BOOL}};

and lines in stdafx.h:
typedef CComQIPtrOffice::_CommandBars OutlookCommandBarsPtr;
typedef CComQIPtrOffice::CommandBar OutlookCommandBarPtr;
typedef CComQIPtrOffice::CommandBarControls OutlookCommandBarControlsPtr;
typedef CComQIPtrOffice::CommandBarControl OutlookCommandBarControlPtr;
typedef CComQIPtrOffice::_CommandBarButton OutlookCommandBarButtonPtr;

extern _ATL_FUNC_INFO DispParamEventHandler;
//////////////----------------------------------------------
-------------------------------///////////////////////////// /


And I'm don't catch button click by such a way, although I catch button
click (using this code) if deal with buttons in main outlook menu, not in
rarely appeared "Appointment window".

How catch in "Appointment" and other windows, appears not just after Outlook
startup ?

Best regards, N.