LNK2019 errors when using 3rd party .dll Visual C++ 2003.NET-Collection of common programming errors

Hello

Is the 3-rd party library a open-source library? I am asking because it provides cpp file and it contain the definition for functions like PortWaitForChar(as you memtioned), does the cpp file contain entire implementation of the library? Being said that if you have the implementation of the library, you are free to build a new set of dll and its import library(.lib) with your visual studio tools on hand.