Visio add text to shape with yellow dot

In detail, it goes something like this:

1. Create or select a shape (duh!)

2. Open the ShapeSheet via Window > Show ShapeSheet

Go to: Insert > Section and check Controls and Text Transform (if it isn’t grayed out)

You should now see both the Controls section and the Text Transform section in the ShapeSheet.

3. In the Text Transform section, set the TxtPin cells as follows:

TxtPinX = Controls.Row_1.X

TxtPinY = Controls.Row_1.Y

4. In the drawing window, reposition the control handle to a suitable default position. The text should follow along!

Taken from: http://www.visguy.com/2009/05/06/top-twelve-text-tips/