Open and write in txt file from Excel macro - excel

Question

I need help with code, I want my macro to open a .txt file and write only 1-9 rows(copy from Excel) in one txt file and then open next .txt file and write 9-18 and so on until data in the excel rows is finished under each column.
Below code only paste 1-9 rows from Excel to Txt file and stop.
So it means if I have 36 rows in Excel(A1-A36) it should create 3 txt files each with 9 rows only.
Sub env_gen()
Dim filename As String
Dim linetext As String
Dim my_range As Range
filename = ThisWorkbook.Path & "\Monday123" & ".txt"
Open filename For Output As #1
Set my_range = Worksheets("sheet1").Range("A1:A9")
For i = 1 To 9
For j = 1 To 1
linetext = IIf(j = 1, "", linetext & ",")
Next j
Print #1, linetext
Next i
Close #1
MsgBox ("File is created")
End Sub

Answer 1

To iterate over a range, you can use a loop and put the index inside the range address. Eg. For i = 1 to 9: Cells(i, 1) = .... This loop can also use the ranges size as a parameter to ensure you loop over the whole range and only the range (no extra). Eg. For i = 1 To my_range.Rows.Count.
When looping within a loop, you can also use the outer loops index as a parameter for the inner loop. Eg. For i = 1 to 36 Step 9: For j = i to i + 8
Here is an example of those techniques implemented with your code:
Sub env_gen()
Dim filename As String
Dim linetext As String
Dim CurrentStep As Long
Dim my_range As Range
Set my_range = Worksheets("sheet1").Range("A1:A36")
For i = 1 To my_range.Rows.Count Step 9
CurrentStep = CurrentStep + 1
filename = ThisWorkbook.Path & "\Monday123 (" & CurrentStep & ").txt"
Open filename For Output As #1
For j = i To i + 8
linetext = my_range.Cells(i).Text & IIf(j <> i + 8, "", ",")
Print #1, linetext
Next j
Close #1
Next i
MsgBox ("Files are created")
End Sub