To use QCard.DLL from C, (I have used it from QCWin, Borland C++ 3.1
and MS Visual C++), put an #include "qcard.h" in your source code. 
Edit your project and add the file QCard.lib to it.
You can now make calls to the DLL just like any other function
calls. You should not have to load and unload QCard.DLL manually
when your program runs. Windows should handle that automatically.
See the help file for a full description of all the functions available
in QCard.DLL.