C++ - Put members in common for two sub classes

Let a library containing the following class hierarchy :

class LuaChunk
{
};

class LuaExpr : public LuaChunk
{
};

class LuaScript : public LuaChunk
{
};

Now I would like to use this library in my application by extending these two classes :

class AppLuaExpr : public LuaExpr
{
private:

    Foo * someAppSpecificMemberFoo;
    Bar * someAppSpecificMemberBar;
};

class AppLuaScript : public LuaScript
{
private:

    Foo * someAppSpecificMemberFoo;
    Bar * someAppSpecificMemberBar;
};

The problem here is that, if I have many members, each of them having its own pair of getter/setter, it's going to generate a lot of code duplication.

Is there a way, that does not use multiple inheritance (which I want to avoid) to put in common the application-specific stuff contained in both AppLuaExpr and AppLuaExpr ?

I've taken a look on the existing structural design patterns listed on Wikipedia, but it doesn't seem like any f these is adapted to my issue.

Thank you.