答：使用程式設計來完成。確保上圖工作表為活動工作表，按ALT+F11組合鍵，開啟VB視窗。執行“插入”-“模組”，複製下面程式碼進去，按F5執行。

Sub Demo()

Dim Cell As Range

Dim DesRng As Range

Dim i As Long

Dim Arr As Variant

Set Cell = Range("A3")

Set DesRng = Range("D3")

Do Until IsEmpty(Cell)

Arr = Split(Cell.Offset(0, 1), ",")

For i = LBound(Arr) To UBound(Arr)

With DesRng

.Value = Cell

.Offset(0, 1) = Arr(i)

End With

Set DesRng = DesRng.Offset(1, 0)

Next

Set Cell = Cell.Offset(1, 0)

Loop

End Sub

執行截圖截圖：