diff --git a/vba_code_common.txt b/vba_code_common.txt
index 125f148..8206d4b 100644
--- a/vba_code_common.txt
+++ b/vba_code_common.txt
@@ -159,7 +159,8 @@ End Sub
 '   dataColumns - array of column numbers to export
 ' Returns: CSV content string
 ' ============================================================
-Function BuildCSVContent(ByVal ws As Worksheet, ByVal startRow As Long, ByVal endRow As Long, ByRef dataColumns() As Long, Optional ByVal headerRow As Long = 0) As String
+Function BuildCSVContent(ByVal ws As Worksheet, ByVal startRow As Long, ByVal endRow As Long, ByVal startCol As Long, ByVal endCol As Long, Optional ByVal headerRow As Long = 0, Optional ByVal colStep As Long = 1) As String
+    ' Simpler version: export continuous columns
     Dim csvContent As String
     Dim r As Long
     Dim col As Long
@@ -167,11 +168,13 @@ Function BuildCSVContent(ByVal ws As Worksheet, ByVal startRow As Long, ByVal en
     
     ' Build header if specified
     If headerRow > 0 Then
-        For col = LBound(dataColumns) To UBound(dataColumns)
-            If col = LBound(dataColumns) Then
-                csvContent = Trim(ws.Cells(headerRow, dataColumns(col)).Value)
+        firstCol = True
+        For col = startCol To endCol Step colStep
+            If firstCol Then
+                csvContent = Trim(ws.Cells(headerRow, col).Value)
+                firstCol = False
             Else
-                csvContent = csvContent & "," & Trim(ws.Cells(headerRow, dataColumns(col)).Value)
+                csvContent = csvContent & "," & Trim(ws.Cells(headerRow, col).Value)
             End If
         Next col
         csvContent = csvContent & vbLf
@@ -179,14 +182,14 @@ Function BuildCSVContent(ByVal ws As Worksheet, ByVal startRow As Long, ByVal en
     
     ' Build data rows
     For r = startRow To endRow
-        If Len(Trim(ws.Cells(r, dataColumns(LBound(dataColumns))).Value & "")) > 0 Then
+        If Len(Trim(ws.Cells(r, startCol).Value & "")) > 0 Then
             firstCol = True
-            For col = LBound(dataColumns) To UBound(dataColumns)
+            For col = startCol To endCol Step colStep
                 If firstCol Then
-                    csvContent = csvContent & CleanCSVField(ws.Cells(r, dataColumns(col)).Value)
+                    csvContent = csvContent & CleanCSVField(ws.Cells(r, col).Value)
                     firstCol = False
                 Else
-                    csvContent = csvContent & "," & CleanCSVField(ws.Cells(r, dataColumns(col)).Value)
+                    csvContent = csvContent & "," & CleanCSVField(ws.Cells(r, col).Value)
                 End If
             Next col
             csvContent = csvContent & vbLf
diff --git a/vba_code_kotsu_master.txt b/vba_code_kotsu_master.txt
index 620813d..c879d0f 100644
--- a/vba_code_kotsu_master.txt
+++ b/vba_code_kotsu_master.txt
@@ -238,23 +238,31 @@ Sub Z1_ExportMasterDetailData()
     savePath = GetSaveCSVPath()
     If savePath = "" Then Exit Sub
     
-    ' Define columns to export (C, I-R = 3, 9-18)
-    Dim dataColumns(0 To 9) As Long
-    dataColumns(0) = 3
-    dataColumns(1) = 9
-    dataColumns(2) = 10
-    dataColumns(3) = 11
-    dataColumns(4) = 12
-    dataColumns(5) = 13
-    dataColumns(6) = 14
-    dataColumns(7) = 15
-    dataColumns(8) = 16
-    dataColumns(9) = 17
-    dataColumns(10) = 18
-    
-    ' Build CSV content (with header from row 5)
+    ' Build header from row 5
     Dim csvContent As String
-    csvContent = BuildCSVContent(ws, 7, lastDataRow, dataColumns, 5)
+    csvContent = Trim(ws.Cells(5, 3).Value)
+    Dim j As Long
+    For j = 9 To 18
+        csvContent = csvContent & "," & Trim(ws.Cells(5, j).Value)
+    Next j
+    csvContent = csvContent & vbLf
+    
+    ' Build data rows
+    Dim r As Long
+    For r = 7 To lastDataRow
+        If Len(Trim(ws.Cells(r, 3).Value & "")) > 0 Then
+            csvContent = csvContent & CleanCSVField(ws.Cells(r, 3).Value)
+            For j = 9 To 18
+                csvContent = csvContent & "," & CleanCSVField(ws.Cells(r, j).Value)
+            Next j
+            csvContent = csvContent & vbLf
+        End If
+    Next r
+    
+    ' Trim trailing
+    Do While Right(csvContent, 1) = vbLf
+        csvContent = Left(csvContent, Len(csvContent) - 1)
+    Loop
     
     ' Count rows
     Dim rowCount As Long