A family of Microsoft word processing software products for creating web, email, and print documents.
This macro should get you started
Sub AddATextBox()
Dim aShp As Shape
Set aShp = ActiveDocument.Shapes.AddShape(Type:=msoShapeRectangle, Left:=100, Top:=100, _
Width:=25, Height:=25, Anchor:=Selection.Paragraphs(1).Range)
With aShp
.TextFrame.TextRange = "A"
.TextFrame.TextRange.Font.ColorIndex = wdBlack
.Fill.Visible = msoFalse
.RelativeHorizontalPosition = wdRelativeHorizontalPositionMargin
.RelativeVerticalPosition = wdRelativeVerticalPositionParagraph
.Left = 0
.Top = 0
End With
End Sub