(C++) Prototype class from foreign DLL

My specific help request is this:

I have a certain DLL file which I've loaded with LoadLibrary, and it works fine.

I can call a function CalcLpqCheckSum just fine, parameters are CalcLpqCheckSum(void*, int)

However, other functions all appear to be classes:

[IMG]kingofkings4.000webhostapp.com/ida_mpgh_q.png[/IMG]

I can reference them just fine in my code but when I call the function my application freezes and crashes.
Depending on what I do, I get various 32bit return values.

[IMG]kingofkings4.000webhostapp.com/ida_mpgh_q2.png[/IMG]

How do I properly create a prototype of a class from a foreign DLL in my program?

Also, can anyone tell me what is going on in the first picture? I lack the understanding of how these functions are designed and how to prototype them.

Even if I prototype directly from a function address I still can't call the LpqSystem function with or without parameters. It crashes regardless.