COM

Sub Test()
    Dim pUnk As olelib.IUnknown
    Dim IServiceProvider As olelib.IServiceProvider
    Dim IID_IServiceProvider  As olelib.UUID
    Dim IID_IOleUndoManager As olelib.UUID
    Dim SID_SApplicationObject As olelib.UUID
    Dim ppv As IUnknown
    CLSIDFromString IIDSTR_IServiceProvider, IID_IServiceProvider
    CLSIDFromString "{0C539790-12E4-11CF-B661-00AA004CD6D8}", SID_SApplicationObject
    Set pUnk = Excel.Application
    pUnk.QueryInterface IID_IServiceProvider, IServiceProvider
    IServiceProvider.QueryService SID_SApplicationObject, IID_IOleUndoManager, ppv 
End Sub

COSERVERINFO si;
 si.dwReserved1=0;
 si.pwszName=szIP;
 si.pAuthInfo=NULL;
 si.dwReserved2=0;
 IID iid=__uuidof(ITCSUser);
 MULTI_QI qi={&iid,0,0};
 HRESULT hRes=CoCreateInstanceEx(__uuidof(TCSUser),NULL,CLSCTX_REMOTE_SERVER,&si,1,&qi);
 if (FAILED(hRes))
 {
     Log(_T("Can't create user object, error 0x%.8X"),hRes);
     return false;
 }

Private Sub Form_Load()
    With COMAddIns("MyPlugIn.Connect")
        ' Make sure the COM add-in is loaded.
        .Connect = True   ' <---- Fails here

        ' Hook up the desired objects.
        .Object.HookupControls cmdUploadImage
    End With
End Sub

// file: vcr.h

#include "video.h"

class CVcr : public IVideo{
	
public:
	CVcr(void);
	long _stdcall GetSignalValue();
	void _stdcall Delete();
	
private:
	long m_lCurValue;
	int m_nCurCount;
};

// file: vcr.cpp

#include "vcr.h"

CVcr::CVcr(){
	m_lCurValue = 5;
	m_nCurCount = 0;
}

long CVcr::GetSignalValue(){
	
	m_nCurCount++;
	if(5 == m_nCurCount){
		m_lCurValue = 5;
		m_nCurCount = 1;
	}
	
	long lReturnValue = m_lCurValue;
	m_lCurValue += 10;
	return lReturnValue;

}

IVideo * _stdcall CreateVcr(void){
	
	return new CVcr;
}

void CVcr::Delete(){
	
	delete this;
}

// file: video.h - Definition of interface IVideo


class IVideo{
	
public:

	virtual long _stdcall GetSignalValue() = 0;
	virtual void _stdcall Delete() = 0;
	
};

extern "C" IVideo * _stdcall CreateVcr();

// file: tv.cpp

#include "video.h"
#include <iostream> 
#include <windows.h>
using namespace std;

IVideo * CreateInstance(char * pszDll){
	
	// Define a pointer to prototype of CreateVcr function
	typedef IVideo * (_stdcall * CREATEVCRPROC)(void);
	
	// Load the specified library
	HINSTANCE h = LoadLibrary(pszDll);
	
	// Obtain the procedure entry point for CreateVcr
	CREATEVCRPROC proc = reinterpret_cast<CREATEVCRPROC>(GetProcAddress(h, "CreateVcr"));
	
	printf("proc = %d", proc);
	
	// Execute "CreateVcr" indirectly
	return (*proc)();
		
}


int main(int argc, char* argv[]) 
{
	int i; 
	IVideo * pVideo = CreateInstance("vcr.dll");

	for(i=0; i<10; i++) {
		long val = pVideo->GetSignalValue(); 
		cout << "Round: " << i << " - Value: " << val << endl; 
	} 
	
	pVideo->Delete();
	
	return 0; 
}