Emulation

I m looking for a test bench/compiler/add-on that will help me import some functions(modules) that I have written for keil ( c program) and compile in VC++.

Precisely this is what I want to do:
I have a function that uses lot of SFR's and bit variables.Now I want to test the function.
But I don't want to run it on any hardware or test it in a debugger. Instead I want to give this module as input to a script that generates lot of various possible combination's of input and provides to the function. Assume there are not any hardware/interrupt related operations necessary.

Problem:
bit variable handling is ok.. but when it comes to sbit... it becomes tedious;

assume I have a bit variable defined as 6th bit of some byte variable
I can always carry AND or OR operation on the BYTE and still the bit will get affected.

How to simulate this behaviour in VC++.
how do i define a bit and then make it part of byte variable.