Adding another param block to helper object

[leaveAlone]

Hello, Does anybody have an example of object with several param blocks and inheritance? What I want to achieve is something like

class ParentHelper
{
IParamBlock2* parentBlock;
};

class ChildHelper : public ParentHelper
{
IParamBlock2* childBlock;
};

One of the problems now is loading of files in old version: childBlock probably gets invalidated at some point and childBlock->SetValue fails.