程序代码：

Private Declare Function SendMessage Lib "user32" Alias "SendMessageW" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Const WM_COPY As Long = &H301
Const EM_SETSEL = &HB1&

Private Sub Command2_Click()
  Text1.Text = Format(Rnd * 100, "#0.0000000")
  SendMessage Text1.hWnd, EM_SETSEL, 0&, -1&    '选择要复制的文本内容,第三个参数是启始位置，第四个参数是结束位置；
  SendMessage Text1.hWnd, WM_COPY, 0&, 0&       '复制Text1中被选中的文本内容。
  MsgBox Clipboard.GetText
End Sub

Private Sub Command1_Click()
  Text1.Text = Format(Rnd * 100, "#0.0000000")
  Text1.SelStart = 0
  Text1.SelLength = Len(Text1.Text)
  Clipboard.SetText Text1.SelText
  MsgBox Clipboard.GetText
End Sub