1) You can trap the error ...

[VBA]
Sub Document_Open()
With Selection
.HomeKey Unit:=wdStory
.TypeParagraph
.HomeKey Unit:=wdStory
On Error Resume Next
.Paste
If Err.Number = 0 Then
.Find.Text = ActiveDocument.Range(0, .Start)
ActiveDocument.Undo 2
.Find.Execute
Else
ActiveDocument.Undo 1
End If
End With
ActiveDocument.Saved = True
End Sub
[/VBA]

2) You can use the browse buttons - below the vertical scrollbar