将键值对数组发送到COM中的API的最佳方法

I want to create an interface with API that can accept array of key-value pairs in COM. What is the best way to do that? I can think of sending SAFEARRAY of BSTR .Each BSTR can be considered as key-value pair . Logic of packing /unpacking key-values need to be added.I want to create an interface with API that can