The most popular posts at Sophisticated Finance over the years have been some posts I did on Excel modeling, which are in the link at left called "Excel Models and Tips". All the posts related to Excel are here.
Some folks sent me the announcement for a world championship of Excel Modeling called Modeloff 2013. This is a cash prize competition to find the best young modeler in the world. Competitors are required to have a knowledge of finance and Excel but statistics also looks helpful.
One of the sample questions from the 2012 competition is here. It is a list of 50 tasks in Excel and the competitors had to identify the Excel command. Also a nice review of advanced Excel commands if anyone wants to improve their skills.