🚀 go-pugleaf

Since all event handlers are "closures" (a pointer to a method in a class) 
you will need an object that handles your ADOp connection and houses the 
event handlers.  Something like this should work for you:

  class TMyDllClass
  {
    private:
      TADOConnection* ADOp;

      void __fastcall ADOpConnectComplete(TADOConnection* Connection,
        const _di_Error Error, TEventStatus &EventStatus);
      void __fastcall ADOpWillConnect(TADOConnection* Connection,
        WideString &ConnectionString, WideString &UserID,
        WideString &Password, TConnectOption &ConnectOptions,
        TEventStatus &EventStatus);

    public:
      TMyDllClass();
      ~TMyDllClass();
  };

  TMyDllClass::TMyDllClass()
  {
    OleInitialize(NULL);

    ADOp = new TADOConnection(NULL);
    ADOp->OnConnectComplete = &ADOpConnectComplete;
    ADOp->OnWillConnect = &ADOpWillConnect;
  }

  TMyDllClass::~TMyDllClass()
  {
    OleUninitialize();
  }

  void __fastcall TMyDllClass::ADOpConnectComplete(TADOConnection* 
Connection,
    const _di_Error Error, TEventStatus &EventStatus)
  {
    // do whatever
  }

  void __fastcall TMyDllClass::ADOpWillConnect(TADOConnection* Connection,
    WideString &ConnectionString, WideString &UserID,
    WideString &Password, TConnectOption &ConnectOptions,
    TEventStatus &EventStatus)
  {
    // do whatever
  }

HTH,
- Clayton