Presumably, since you're now working with inlineshapes, the code would become:
Code:
Sub Demo()
Dim iShp As InlineShape
With Selection ' or ActiveDocument
For Each iShp In .InlineShapes
With iShp
.LockAspectRatio = True
.Height = CentimetersToPoints(3.5)
With .Line
.ForeColor.RGB = RGB(0, 0, 0)
.Weight = 0.5
.Visible = True
.Style = msoLineSingle
End With
With .Range.ParagraphFormat
.Alignment = wdAlignParagraphCenter
.LineSpacingRule = wdLineSpaceSingle
End With
End With
Next
End With
End Sub