Add-In Development

What is an Excel Add-In

An Excel VBA add-in is a file (usually with an .xlam or .xla extension) and an installable program designed in VSTO that Excel can load when it starts up. The file contains code (VBA in the case of an .xlam add-in) that adds additional functionality to Excel, usually in the form of new functions. These functions can be used on all your Excel workbooks for repetitive tasks and to automate your processes.

Add-Ins Created in Excel

Add-in files created in Excel are Excel workbooks saved with an add-in extension. In Excel 2007 and above, the ribbon or toolbar can be customised and buttons added to run VBA Macros. Add-in files are then loaded into either the add-in or start up directories in Excel on a user’s PC. The files are then loaded when excel starts up and all the VBA macros are available to all workbooks.

Larger organisations often modify their login scripts so that these add-ins files are installed into the correct location when user’s logon, thus adding their features seamlessly to a user’s PC.

Add-Ins Created in VSTO (Visual Studio Tools for Office)

VSTO is a set of development tools available with Microsoft Visual Studio that supports the Microsoft .NET Framework. It is used by developers to write code connecting Microsoft Office applications. Developers using VSTO can use .NET languages, instead of using VBA. VSTO add-ins are installed on a PC and are compiled applications. From a security point of view add-ins are perfect to distribute code that you want to protect.

VBA or VSTO Add-ins, which is best for you?

This really depends on your requirements. If the code that you need developed is specific to an individual workbook or a few workbooks, then add-ins really are not best solution. If the code you want is required for all workbooks, then an add-in could be a good solution.

If the add-ins features are for your organisation only and security and deployment is not an issue, then a VBA add-in will suit your needs. Otherwise a VSTO add-in may be required.

Help Designing Add-Ins from Excel Expert’s Developers

Excel Experts has developers can work in all areas of add-in development. If you need help designing or determine what is best for your organisation, then our experienced Excel programmers can help analyse and develop a solution that suits your organisations requirements. Give us a call or send us an email and an experienced consultant will help you out.