Ricky,
If you want to call a COM component from .NET, you just have to add a
reference to it in your VS.NET project (go to "Add References").
If you were working from the command line, you would run the TLBIMP
utility to generate a Runtime Callable Wrapper, and then set a reference to
that.
You can also call C++ code through the P/Invoke layer, if the C++ code
exposes functions through a DLL.
Or, finally, you can wrap the C++ code in a managed wrapper (using
Managed Extensions for C++) and then call it like a normal assembly.
Hope this helps.