Hola talvez te pueda servir esto....
Código:
Dim numTexBox As Integer = 5
Dim i As Integer
For i = 0 To numTexBox - 1
Dim txt As New TextBox
txt.Name = "txtNum" & i
txt.Width = "40"
txt.TextAlign = HorizontalAlignment.Center
txt.Location = New Point(40 + (50 * i), 120)
Controls.Add(txt)
Next