OlkCommandButton Object (Outlook)
A control that supports a user action specified as a command.
Before you use this control for the first time in the forms designer, add the Microsoft Outlook Command Button Control to the control toolbox. You can only add this control to a form region in an Outlook form using the forms designer.
The following is an example of the command button control at runtime. This control supports Microsoft Windows themes.
For more information about Outlook controls, see Controls in a Custom Form. For examples of add-ins in C# and Visual Basic .NET that use Outlook controls, see code sample downloads on MSDN.