How to arrange strings like that?

[Code Doc]

Is this what you need? Put a command button, a textbox and a listbox on a form....put your string in the textbox and click on the cmdbtn

private sub Command1_click()
Dim x As Integer, y As Integer, myText As String
myText = Trim(Text1.Text)
y = 0
For x = 1 To Len(myText) - 1
    myText = Left(myText, 0 + (y)) & Mid(myText, y + 1, 1) & "," & Mid(myText, y + 2)
    List1.AddItem myText
    y = y + 2
Next x
End Sub

That misses many possibilities. Take a look at the list in Post #5.