There are two main problems that you are facing:
1. The name of the function needs to be exposed to the "outside world" so the linker can see it.
2. You need to see that the function name is not "mangled" (Microsoft calls this "decorated").
I am not familiar with the 2005 compiler, but I know that the earlier compilers have examples and/or code generators that will do both of these things.
It might be easier for you to create a new progect that exports the symbols properly and copy the code into them or use the generated code as an example to fix your existing code.
Regards,
rich
P.S. If you want, let me know and I will work up an example using the earlier version compiler.