Excel Dev Conf Presenter – Charles Williams

What’s your job?
I am Decision Models Ltd – Excel consultancy & micro ISV

What’s your Topic?
VBA to C – Pratfalls and Perils of a C++ Newbie

My FastExcel product contains about 8K lines of VBA UDFs designed to speed up Excel calculations. For the next version I am rewriting and extending them using C++ XLLs (see Excel UDF Technology choices for some of the reasons behind this).

So the idea of this session is very much to approach C++ XLL’s from the viewpoint of a VBA developer, and talk about my journey from VBA developer to C++ newbie.

I plan to demonstrate developing and debugging some XLL UDFs using Planatech XLL+ and Visual Studio 10, along with some of the embarrassing mistakes that I keep on making (but you aren’t allowed to laugh), and a few of the things that I still don’t properly understand (string handling/functions !*#!).

The session will hopefully demolish some of the myths surrounding XLL development.
If there is time I will show how using the STL and BOOST libraries and XLL+ UDF wizards make it easy to add powerful features such as multi-threaded global memory caches to your UDFs.

How did you get to be an Excel Speed Geek?

I spent many years with IBM in a wide variety of different roles, until the time came to part. Then in 1996 I started my Excel consultancy and development business. And somehow along the way I became an Excel Geek obsessed with ways of making Excel calculate faster.

What else do you do?


One Response to “Excel Dev Conf Presenter – Charles Williams”

  1. Excel Developers’ Conference Jan 25 London report | Patrick O'Beirne @ sysmod Says:

    […] Charles Williams  recounted his experience of migrating 8000+ lines of VBA code in his FastExcel addin to C++. This was necessitated by the introduction of the 64-bit version of Excel. To save him time, he used the Plantech XLL+ addin for Visual Studio and the STL/Boost library. His blog at decisionmodels.com is worth following for tips on improving Excel performance which can be better done by more efficient algorithms than language tweaks. […]

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