Code:
Private Sub Command1_Click()
    Call DrawBorder(Label1, vbRed)
End Sub

Private Sub DrawBorder(lbl As Label, Color As OLE_COLOR)
    With lbl
        Me.Line (.Left, .Top)-(.Left + .Width - Screen.TwipsPerPixelX, .Top + .Height - Screen.TwipsPerPixelY), Color, B
    End With
End Sub