[Solved] Column nullification using Vbscript

Question

EDIT:??

EDIT: ADD MY SAMPLE INPUT & OUTPUT RESULT

EDIT: Variable added, ChuckSize

EDIT: also change the lane startCol = objSheet1.Range("A1").column
The “A” to “S”, to whatever column your PID is at,
assumption made: Your data starts from row 1

A solution using @Tim’s Solution + the 2D Array optimization tech.

Sample Input:

A   A   A   A   A   A   A   A   A   A   PID T1Name  T1StartDate T1FinishDate    Total Time Spent    T2Name  T2StartDate T2FinishDate    Total Time Spent    T3Name  T3StartDate T3FinishDate    Total Time Spent
A   A   A   A   A   A   A   A   A   A   11  S1  12/7/2012   19/7/2012   100                         19/7/2012   
A   A   A   A   A   A   A   A   A   A   12  S1  12/7/2012                           S2      19/7/2012   
A   A   A   A   A   A   A   A   A   A   13  12/7/2012                   11/5/2012           S6      12/5/2010

Sample Output:

A   A   A   A   A   A   A   A   A   A   PID T1Name  T1StartDate T1FinishDate    Total Time Spent    T2Name  T2StartDate T2FinishDate    Total Time Spent    T3Name  T3StartDate T3FinishDate    Total Time Spent
A   A   A   A   A   A   A   A   A   A   11  S1  12/7/2012   19/7/2012   100                             
A   A   A   A   A   A   A   A   A   A   12                                              
A   A   A   A   A   A   A   A   A   A   13

Code:

 Option Explicit

  Dim objExcel1,objWorkbook
  Dim strPathExcel1
  Dim objSheet1,IntRow1
  Dim Counter
  dim height
  dim i 
  dim dataArray
  dim startCol 
  dim j 
  dim chuckSize 
   Set objExcel1 = CreateObject("Excel.Application")
   strPathExcel1 = "C:\Users\wangCL\Desktop\data.xlsx"

   Set objWorkbook=objExcel1.Workbooks.open(strPathExcel1)
   Set objSheet1 = objExcel1.ActiveWorkbook.Worksheets("data (4)")

   objExcel1.ScreenUpdating = False
   objExcel1.Calculation = -4135  'xlCalculationManual
   startCol = objSheet1.Range("K1").column 'column with PID is 
   chuckSize = 4
   Height = objSheet1.Cells(objSheet1.Rows.Count, startCol).End(-4162).Row '-4162 is xlUp
If Height >= 2 Then
    ReDim dataArray(Height - 2, 12) '12 columns in total
    dataArray = objSheet1.Range(objSheet1.Cells(2, startCol + 1), objSheet1.Cells(Height, startCol + 12)).Value
    For i = 1 To Height - 1
        For Counter = 1 To 12 Step chuckSize
        If dataArray(i, Counter + chuckSize-1) = "" Then
            For j = 0 to chuckSize - 2
            dataArray(i, Counter + j) = ""
            next 
        End If

        Next
    Next
    'assigning the values back into the worksheet
    objSheet1.Range(objSheet1.Cells(2, startCol + 1), objSheet1.Cells(Height, startCol + 12)).Value =     dataArray
End If

   objExcel1.ScreenUpdating = True
   objExcel1.Calculation = -4105   'xlCalculationAutomatic

  '=======================
 objExcel1.ActiveWorkbook.Save
 objExcel1.Workbooks.close
 objExcel1.Application.Quit
 '======================

Accepted Answer