Where to insert progressbar macro in mulitple for loops

[waimea]

Sub InitProgressBar()
With Progress
   .Bar.Width = 0
   .Text.Caption = "0% Complete"
   .Show vbModeless
End With

End Sub

Sub TestProgressbar()

Dim CurrentProgress As Double
Dim ProgressPercentage As Double
Dim BarWidth As Long

Dim L As Integer
Dim N As Integer

Sheets("Dash").ComboBox1.ListIndex = 1

For L = 0 To 39

Call InitProgressBar

CurrentProgress = L / ?????
BarWidth = Progress.Border.Width * CurrentProgress
ProgressPercentage = Round(CurrentProgress * 100, 0)

Progress.Bar.Width = BarWidth
Progress.Text.Caption = ProgressPercentage & "% Complete"

DoEvents

Sheets("Dash").ComboBox2.ListIndex = L
Sheets("Dash").ComboBox3.ListIndex = 1

For N = 0 To 39
Sheets("Dash").ComboBox4.ListIndex = N

Next
Next

End Sub

I have an userform named Progress and I am using two for loops and I am having trouble with what value I should put in the CurrentProgress variable??

CurrentProgress = L / ?????

I have tried 1600 (40*40), 800 and I want help with what value I should use and where to put the progressbar code??