IRichEditOle:GetObject 是如何个用法

IRichEditOle::GetObject 是怎么个用法
IRichEditOle::GetObject  
怎么用啊

哪个给个例子

看了msdn     不知道第一个参数怎么用?
每次返回值都不成功

------解决方案--------------------
iob
Zero-based index specifying which object to return information about. If this parameter is REO_IOB_USE_CP, information about the object at the character position specified by the REOBJECT structure is returned.