DLL problem with Visual C++ 6.0

Hello,

I am trying to build an application to display curves from data coming through a USB device.

I cannot go from a white paper so I have found realtime_plot.zip which compiles with Visual C++ 6.0 with MFC. The express versions are difficult to use even with multiple topics about MFC. I have also found hidioc.zip another application to demonstrate usage of HID USB.

Now I have a workspace with 3 projects. The first and second come from the graphic demonstration, the plot functions are in a DLL with a class clPlot.

I have tried to copy a small struct of this DLL to make a new DLL in the third project, including a small part of the USB functions whith a class clUsb.

The three parts compile separately without error or warning. But I cannot call an USB function or instantiate the clUsb. Perhaps I have made a mistake in copying and adapting the different blocks ???

The first step gives:

error C2653: 'clUsb' : is not a class or namespace name
error C2065: 'FindTheHID' : undeclared identifier

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I suppose the linker does not find where the function is.

For the second try I have :

error C2146: syntax error : missing ';' before identifier 'm_Usb'
error C2501: 'clUsb' : missing storage-class or type specifiers

Click to expand...

I don't know how to progress, the different explanations of these errors on the net gave me no help. Can someone help me ? Thanks.