Task panes don’t have a dedicated visual designer because they are implemented through the creation of a user control, which already has a design surface. To add a custom task pane to your Word add-in, right-click the project, select Add New Item, and then select the Windows Forms User Control item.
Because actions panes are document-level concepts, you’ll read about those separately in the section “Creating an Office Document Extension,” later in this chapter. You follow the same general development process.
After the user control is added and the designer is loaded, you can set about creating the UI and code-behind for the task pane. The only Office-specific action item here is wiring the task pane user control ...