well, I have another method which is inspired from wingcom's method, but doesn't use conditions:
CODE
Option Explicit
Private Const mLoop As Integer = 5
Private mValue As String
Private Sub Command1_Click()
Dim i As Integer
mValue = "1"
List1.AddItem (mValue)
For i = 2 To mLoop
mValue = mValue & CStr(i)
List1.AddItem (mValue)
Next i
End Sub
nested loop example(because you wanted it so):
CODE
Option Explicit
Private Const mLoop As Integer = 5
Private mValue As String
Private Sub Command1_Click()
Dim i As Integer
Dim j As Integer
For i = 1 To mLoop
mValue=""
for j=1 to i
mValue = mValue & CStr(j)
next j
List1.AddItem (mValue)
Next i
End Sub