ContainingRange Property
Returns a Range object that represents the entire story in a series of shapes with linked text frames that the specified text frame belongs to. Read-only.
Example
This example checks the spelling in TextBox 1 and any other text in text frames that are linked to TextBox 1.
Dim rngStory As Range
Set rngStory = ActiveDocument.Shapes("TextBox 1") _
.TextFrame.ContainingRange
rngStory.CheckSpelling