Adding transient attribute to standard VO

OAApplicationModule am = pageContext.getApplicationModule(webBean);
OAViewObject vo=(OAViewObject)am.findViewObject("ListVO");
if(!vo.isPreparedForExecution()){
vo.executeQuery();
}

if(cvo!=null){
try{
String transientAttr=cvo.findAttributeDef("XXAttr").toString();
}catch(Exception e){
vo.addDynamicAttribute("XXAttr");
}