Hello,I walked this same path a few months ago. You have several options but if you just want to get the job done and you are not interested in becoming an expert in all of the intracacies, then you should download XLW which is a wrapper for all of the excel calling specifics written in c++. Also, since you are on this forum, you might want to download QUANTLIB which is a collection of useful C++ functions and classess which integrates nicely with XLW (since your goal is to make excel XLLs...a renamed DLL). Both of these are available free (open source) at Sourceforge. Once you get the hang of it, these tools make it real easy.http://sourceforge.net/projects/quantli ... e.net/Rick