C# doesn't have include files like C and C++ do. Nor does it have .lib files like those languages do.
Assuming the file you received is a .NET assembly, all you should have to do is copy it into the bin\debug directory in your project, then add a reference in the project explore. You set a reference by right-clicking on "References" then choose "Add..". In the dialog, click the browse button and find your assembly. Select it, then click "OK". In your .cs file, put a "using" statement at the top.
Chip H.
____________________________________________________________________
If you want to get the best response to a question, please read FAQ222-2244 first