How can i get data from REMOTE database using OnStart method?

 protected override int OnStart(StudyLoaderArgs studyLoaderArgs)
        {
            ApplicationEntity ae = studyLoaderArgs.Server as ApplicationEntity;
            _ae = ae;

            EventResult result = EventResult.Success;
            AuditedInstances loadedInstances = new AuditedInstances();
            try
            {

                XmlDocument doc = RetrieveHeaderXml(studyLoaderArgs);
                StudyXml studyXml = new StudyXml();
                studyXml.SetMemento(doc);

                _instances = GetInstances(studyXml).GetEnumerator();

                loadedInstances.AddInstance(studyXml.PatientId, studyXml.PatientsName, studyXml.StudyInstanceUid);

                return studyXml.NumberOfStudyRelatedInstances;

            } 
            finally 
            {
                AuditHelper.LogOpenStudies(new string[] { ae.AETitle }, loadedInstances, EventSource.CurrentUser, result);
            }
        }

i need to use OnStart in main project. How cn i use or call OnStart method