在RichEdit插入多张位图,右键选中时,怎样才知道当前选取取的是那一张位图

RichEdit插入多张位图,通过:
int c = GetIRichEditOle()->GetObjectCount();
for(int i = 0 ; i < c ; i++) //遍历位图
    {
       REOBJECT reobject;
       ZeroMemory(&reobject, sizeof(REOBJECT));
       LPOLEOBJECT m_lpObject;
       reobject.cbStruct = sizeof(REOBJECT);
       GetIRichEditOle()->GetObjec   (i,&reobject,REO_GETOBJ_ALL_INTERFACES);//REO_GETOBJ_ALL_INTERFACES); }
得到所有们图,但怎样才知道当前选取取的是那一张位图了?