Excel Tools and Utilities

Types of Resources

Although the range of available tools is enormous, underneath the covers almost all of these resources consist of one or more basic Excel objects:

• Add-ins. An Excel add-in is a generalized custom function that can be used with any worksheet. An add-in is saved as its own worksheet, usually with an .xla extension, and can be used with any worksheet or workbook, just like a built-in Excel function.
• Custom functions. In addition to a variety of built-in functions, Excel provides an easy way to create your own functions. One limit on custom functions is that they’re attached to a particular worksheet. If you want to use a custom function with another worksheet, you either have to import the custom function or reference it via the worksheet where it resides. Custom functions can be written in Excel native commands, Visual Basic for Applications (VBA), C#, or C.
• Templates. In essence, a template is a more general version of a prewritten spreadsheet. It includes formatting and perhaps some (but not all) of the formulas and such you need to complete the job. Templates are usually saved with the extension .xlt.
• Worksheets. Prewritten worksheets can include labels, formulas, and the rest of the data and programming you need already in place.

Any of these objects, or any combination of them, can be used to write utilities and applications for Excel.

Tools for Excel Programming

Worksheet Auditors
One of the most useful programming applications is an auditor to check your worksheets for errors:
CheckXL [1]
The Spreadsheet Detective [2]

Add-In Decompilers
The Excel add-in decompiler [3] converts Excel add-ins back into regular Excel workbooks. This tool is valuable if you’re customizing Excel add-ins.