MT4 C++ DLL project

I have a couple of profitable MT4 Expert Advisors which I wish to sell commercially. The project involves writing a C++ DLL which would contain certain functions ordinarily within the EX4 file. My idea is that these functions could be simple text strings. The EA would call the strings from the DLL and convert them to doubles inside the EX4 file. Unauthorised decompilation of the EX4 would then yield meaningless source code. The DLL would additionally contain time expiry and account locking code. I require a template DLL including the CPP and definition source files so that I can insert the strings and locking data before issuing individual compiled DLLs. I intend to use Visual C++ 2008 Express to compile the DLLs.