Option Explicit

Sub InsertHorizontalLine()
Dim shpLine As InlineShape
Dim oShape As InlineShape
Dim orng As Range
    Set orng = Selection.Range
    ' Check the previous paragraph
    If Not orng.Start = ActiveDocument.Range.Start Then
        If orng.Paragraphs(1).Previous.Range.InlineShapes.Count > 0 Then
            Set oShape = orng.Paragraphs(1).Previous.Range.InlineShapes(1)
            If oShape.Type = 6 Then
                MsgBox "Line exists in the previous paragraph?"
                GoTo lbl_Exit
            End If
        End If
    End If
    ' Check the current paragraph
    If orng.Paragraphs(1).Range.InlineShapes.Count > 0 Then
        Set oShape = orng.Paragraphs(1).Range.InlineShapes(1)
        If oShape.Type = 6 Then
            MsgBox "Line exists in the current paragraph?"
            GoTo lbl_Exit
        End If
    End If
    ' Create the line
    Set shpLine = orng.InlineShapes.AddHorizontalLineStandard
    ' Line size and alignment
    shpLine.HorizontalLineFormat.PercentWidth = 80
    shpLine.HorizontalLineFormat.Alignment = wdHorizontalLineAlignRight
lbl_Exit:
    Exit Sub
End Sub