Calling a .NET library (.dll) from a Qt application

Hello,
I am conducting a research about text clustering and have found a third party library written in .NET. However, I haven't used .NET and am not familiar with VS .NET environments. I would like to use the library I found in my pure c++ application. I googled and found some possible ways to do that. For example ActiveQt
To be honest, I didn't find it useful for my purpose because it only demonstrates how Qt objects can be used in a .NET environment not how .NET objects can be used in a Qt environment.

I have a few questions.

Should I modify the source code of the library I found such as making it a COM object?
If so, how?
I guess it's possible to call the library as a COM object from Qt. But I am not sure how to do that.

Second question is, is there anyone who had a similar problem and have managed to solve it or is there any descriptive tutorial I can follow?

The question is pretty simple, I need to call a third party .NET dll in Qt.

Hope you can help me.

Thanks