To what I think Borland C++ is a very old and outdated compiler (what I think), MingW and Cygwin easily beat Borland, as you can see on the Wikipedia Page Borland's last stable release was in 1999
Now to your question :
You are trying to Link to extremely different things together, which in fact is possible, but will be extremely tough as SA said.
A google hit on
using c# dll in c++ (Note that those people might use Other C++/C Compilers)
gave me this :
http://www.cplusplus.com/forum/windows/77244/[
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And here's some info from this thread
http://stackoverflow.com/questions/3799907/using-c-sharp-dll-in-project-c[
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2.2 How do I call .NET assembly from native Visual C++?
There are basically four methods to call .NET assembly from native VC++ code. Microsoft All-In-One Code Framework has working examples that demonstrate the methods.
Native VC++ module calls CLR Hosting APIs to host CLR, load and call the .NET assembly. (All-In-One Code Framework Sample Code: CppHostCLR)
If the .NET assembly can be exposed as a COM component, native VC++ module can call into the .NET assembly through .NET – COM interop. (All-In-One Code Framework Sample Code: CppCOMClient)
Reverse PInvoke: the managed code call native passing a delegate the native code can call back. (All-In-One Code Framework Sample Code: CSPInvokeDll)
If the module containing native VC++ code is allowed to enable CLR, the native VC++ code can call .NET assembly directly through the "It Just Works", or "IJW", mechanism. (All-In-One Code Framework Sample Code: CppCLIWrapLib)
Also you can use SWIG (Simplified Wrapper and Interface Generator)
http://www.swig.org/[
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