This was solved for me by WINKO - THANKS!!:

Sub Keep_specific_columns1()
'
' DeleteColumnsOnSheet Macro
' Developer: Winko Erades van den Berg
' E-mail : winko at winko-erades.nl
' Developed: 09-03-2012
' Modified: 09-03-2012
' Version: 1.0
'

Dim iCol As Long

'Constant values
data_sheet1 = InputBox("TEST1:") 'Create Input Box to ask the user which sheet needs to be reorganised

'Start with counting columns
For iCol = 1 To Sheets(data_sheet1).UsedRange.Columns.Count

'Read the header of the sheet to determine whether the column needs to be deleted
TargetCol = 0
If Sheets(data_sheet1).Cells(1, iCol).Value = "L72A" Then TargetCol = 1
If Sheets(data_sheet1).Cells(1, iCol).Value = "L73A" Then TargetCol = 1
If Sheets(data_sheet1).Cells(1, iCol).Value = "L74A" Then TargetCol = 1

'If a column doesn't match then delete column
If TargetCol = 0 Then
Sheets(data_sheet1).Columns(iCol).Delete
If iCol < Sheets(data_sheet1).UsedRange.Columns.Count Then
iCol = iCol - 1
Else
End If
End If

Next iCol 'Move to the next column until all columns are read

End Sub