Maybe something like
Code:
Dim orng As Range
Dim octrl As Object
Set orng = ActiveDocument.Range
orng.Collapse 0
Set octrl = orng.InlineShapes.AddOLEControl(ClassType:="Forms.TextBox.1")
octrl.Height = InchesToPoints(0.25)
octrl.Width = InchesToPoints(3)
orng.InsertParagraphAfter