How to Access a C++ lib that is linked into a Fortran dll from C#

Hi,

this one sounds more complicated then it is.

I have a C++ lib that is linked into a Fortran dll. Now I want to access some functions of this C++ lib from a C# program. But the program doesn´t find the entry point. Calling Fortran routines is no problem.

Could it be that I can just call the C++ lib from the Fortran dll and not from a program that uses that dll?

Thanks in advance,
Markus