how to loop a vba code

[kxlvba]

I have the following piece of code which I'd used in a form. However, with this I could only do entry in one worksheet at a time.

The code was,

Sub update_Click()
Dim iRow As Long
Dim ws As Worksheet
Set ws = Worksheets(CStr(Worksheets("Data List").Cells(4, 18).Value))

'find first empty row in database
iRow = ws.Cells(Rows.Count, 2) _
.End(xlUp).Offset(1, 0).Row
............................

Now, I need to enter the same data inputed into multiple worksheets. Hence, I made the following changes.

Sub update_Click()
Dim iRow As Long
Dim ws As Worksheet
Dim rng1, rng2 As Integer

Set rng1 = Worksheets("Data List").Cells(4, 18).Value
Set rng2 = Worksheets("Data List").Cells(9, 18).Value

Set ws = Worksheets(CStr(Worksheets("Data List").Cells(4, 18).Value))

'find first empty row in database
iRow = ws.Cells(Rows.Count, 2) _
.End(xlUp).Offset(1, 0).Row
............................

I have all worksheets named as numbers, i.e. 1, 2, 3, 4, etc.

On one worksheet named "Data List" I get the Start Date and End Date.
Obviously the cell value is (4, 18) and (9, 18) is the reference point.


I now wish to run the above code through a loop,
i.e. if I enter Start Date as 5 and End Date as 9, then I need to make the same entry in worksheets 5, 6, 7, 8, 9.

or if the start date is 21 and end date is 30 then I need to make the same data entry in worksheets named, 21, 22, 23, 24, 25, 25

The second piece of code is still been developed, hence not complete.

Please help.