Sub InsertPDF()
'Graham Mayor - http://www.gmayor.com - Last updated - 04/03/2017
Dim strPDF As String
Dim oRng As Range
    Set oRng = Selection.Range
    strPDF = BrowseForFile
    If Not strPDF = vbNullString Then
        oRng.Text = ""
        ActiveDocument.InlineShapes.AddOLEObject _
                ClassType:="AcroExch.Document.DC", _
                FileName:=strPDF, _
                LinkToFile:=False, _
                DisplayAsIcon:=False, _
                Range:=oRng
    End If
lbl_Exit:
    Exit Sub
End Sub

Private Function BrowseForFile() As String
'Graham Mayor - http://www.gmayor.com - Last updated - 04/03/2017
Dim fDialog As FileDialog
    On Error GoTo Err_Handler
    Set fDialog = Application.FileDialog(msoFileDialogFilePicker)
    With fDialog
        .Title = "Select the document to insert"
        .AllowMultiSelect = False
        .Filters.Clear
        .Filters.Add "PDF Format", "*.pdf"
        .InitialView = msoFileDialogViewTiles
        If .Show <> -1 Then GoTo Err_Handler:
        BrowseForFile = fDialog.SelectedItems.Item(1)
    End With
lbl_Exit:
    Exit Function
Err_Handler:
    BrowseForFile = vbNullString
    Resume lbl_Exit
End Function