The SqPlus Wiki-site
http://wiki.squirrel-lang.org/default.aspx/SquirrelWiki/SqPlus.html states that "C++ classes can inherit from Squirrel classes". If someone could give me a hint on how to do that I might be a step closer to what I want to accomplish.
Another possibility would be to create a vector/array of SquirrelObjects, although I'm not sure it would work the same way I want it to...