Video HowTo: Resize Advanced Task Pane programmatically (VB.NET)
To resize your custom Office task pane, you need to use the trivial Width and Height properties of the particular instance of your task pane. There is just one important thing – the Splitter property should be set to None.
Now let’s see how it works:
This sample video was captured in Visual Studio 2008 (VB.NET) with Add-in Express 2009 for Office and .net.