[UnmanagedFunctionPointer(System.Runtime.InteropServices.CallingConvention.Winapi)]
         public delegate string NativeDelegate(string par);
         public static NativeDelegate function;

          unsafe public string CallFunct(int adress)
         {
             function = (NativeDelegate)Marshal.GetDelegateForFunctionPointer((IntPtr)adress, typeof(NativeDelegate));
             string tst = function("hello");
             return tst + "_callFunct" ;
         }

public delegate string NativeDelegate( [MarshalAs(UnmanagedType.AnsiBStr)] string par);