Excel allows you to create your own "User Defined Functions" (UDF) that can be used the same way as any other built-in function in Excel (i.e. IF, SUM, VLOOKUP, etc.).  With a little knowledge of VBA code, you can create your own function to do pretty much whatever you want. To illustrate how to create a UDF, we'll create a function that calculates fuel consumption in miles … [Read more...]