vbscript Excel Match Function - excel

Question

I have a worksheet with some 100k rows by perhaps 2 dozen columns. Presently I am coloring a specific column, say "ABC", that when the value is > x set the interior.colorindex to y. At the moment I have to sort this column descending, then using a FOR EACH statement, cycle through each of the row cells until the value < x, coloring the cell as each NEXT is reached.
What I am trying to be is make this far more efficient by using the Excel MATCH function, find the last row number, then color the cells in one block rather than individual cells but cannot get my clumsy coding to work correctly. Everything I have read appears to indicate that the MATCH function is supported in vbscript, but I need some assistance from some kind soul figure this out. I have trimed my code down to the relevant section and would appreciate and assistance provided. Please forgive my ignorance, I am very new to this coding thing, and this is my first post requesting help.
Dim objXLApp, objXLWb, objXLWs, objWorksheet, WorksheetFunction
Dim InFile, OutFile
Dim ObjRange, ObjRange2, ObjRange3, rng, rng1, rng2, trng
Dim iRows, iCols, iR, iC, lRow, fRow, col, rw, tRow
Dim ColSearch, StartTime, EndTime, TotalTime
Dim cTeal, cPurple, cCyan, cVal, opVal
Dim Counttcolor, Countpcolor, Countccolor, clr
Dim vMsg
' input parameters
InFile = Wscript.Arguments.Item(0)
OutFile = Wscript.Arguments.Item(1) 'this output file CAN be the same as the input thereby overwriting if required.
Set objXLApp = CreateObject("Excel.Application")
'application function SWITCHES - set to TRUE to enable
objXLApp.Visible = True
objXLApp.EnableEvents = True
objXLApp.DisplayAlerts = True
objXLApp.ScreenUpdating = True
objXLApp.DisplayStatusBar = False
vMsg = 1 ' set to 1 to turn on timer prompts for each processing section
Set objXLWb = objXLApp.Workbooks.Open(InFile)
'Select the appropriate Sheet in the Workbook
Set objXLWs = objXLWb.Sheets(1)
objXLWb.Sheets(1).Activate
objXLWs.DisplayPageBreaks = False
'decleration must be AFTER opening the input file
objXLApp.Calculation = xlCalculationManual
objXLApp.CalculateBeforeSave = True
' Set range and count Row & Columns
Set objRange = objXLWs.UsedRange
iRows = objRange.Rows.Count
iCols = objRange.Columns.Count
'MsgBox iRows
'MsgBox iCols
StartTime = Timer()
ColSearch = "ABC" 'COLUMN AS
For iC = 1 To iCols
If InStr(objRange.Item(1, iC).Value2,ColSearch) Then
'sort the column descending to bring highest records to the top
Set objRange = objXLWs.UsedRange
Set objRange2 = objXLApp.Range(objRange.Item(2, iC).Address) 'ABC
objRange.Sort objRange2, xlDescending, , , , , , xlYes
cTeal = 15 'set the teal minimum value
'set the range for the match function to search for the min cTeal value
rng = objRange.Item(2, iC).Address &":"& objRange.Item(iRows, iC).Address
'search for the first row number containing the first value less than cTeal
tRow = objXLApp.match(cTeal, rng, -1)
MsgBox tRow 'this presently fails here with object required if commented fails at set trng with reference to tRow variable
'set the range for coloring the entire block of cells
Set trng = objRange.Item(2, iC).Address &":"& objRange.Item(tRow, iC).Address
objXLApp.Range(trng).Interior.ColorIndex = 42 'Teal
End If
Next
EndTime = Timer()
If vMsg = 1 Then MsgBox "ABC: " & FormatNumber(EndTime - StartTime, 2)

Answer 1

Problem solved, it was a range issue. Needed to set the range to a single column (ie: A:A and not the cell references as existed) but I had something wrong in my existing code. Thanks anyway.
For reference sake, here is the working code:
ColSearch = "ABC"
For iC = 1 To iCols
If InStr(objRange.Item(1, iC).Value2,ColSearch) then
'to get the column letter for setting the rng param for match function
col_letter = Split(objRange.Item(1, iC).Address, "$")(1)
cTeal = 14
cPurple = 5
'set the range address string
col_letter = col_letter & ":" & col_letter
'set the range to a single column letter/name for the match function
set rng = objXLApp.Range(col_letter)
tRow = objXLApp.Match(cTeal,rng,-1) 'find the last row for Teal value
pRow = objXLApp.Match(cPurple,rng,-1) 'find the row for Purple value
'Msgbox tRow
'Msgbox pRow
objXLApp.Range(objRange.Item(2, iC).Address & ":" & objRange.Item(tRow, iC).Address).Interior.ColorIndex = 42 'Teal
objXLApp.Range(objRange.Item(tRow+1, iC).Address & ":" & objRange.Item(pRow, iC).Address).Interior.ColorIndex = 34 'Cyan
objXLApp.Range(objRange.Item(pRow+1, iC).Address & ":" & objRange.Item(objRange.Item(2, iC).End(xlDown).Row, iC).Address).Interior.ColorIndex = 39 'Purple
End If
Next