Busy times at Microsoft has meant that I've been slower than usual in posting recently. My current expectation is to be over my heavy workload by about mid-June. I'll continue to post in the meantime; but at a slower pace. TechEd is being held in Orlando...

Writing our own, custom worksheet functions is a great way to extend Excel. Before Excel 2002 we developed custom functions by either writing them using VBA inside an XLA or by using C/C++ inside an XLL. Excel 2002 introduced a new type of addin called...

One other area I work in is Business Intelligence. These days BI is an important technology to an increasing number of companies. There are many great BI tools out there, one of which is (of course) Excel. One of the things that makes Excel such a...

Office Open XML (OOXML), the XML file formats used by Office 2007, today won the ISO vote which paves the way for it becoming an ISO standard. This is very exciting news indeed for Excel programmability. Coupled with the new Open XML SDK that we announced...