How to find and replace the column name?

Question

I am trying to find and replace the column name.

I want to loop in the first row only but my code loops the entire sheet.

Dim sht As Worksheet
Dim fndList As Variant
Dim rplcList As Variant
Dim x As Long
Dim data As Variant

Set sht = ActiveWorkbook.Worksheets("ERT")

fndList = Array("colon.", _
                "Selec:", _
                "Sele, _
                "Submi")
                
rplcList = Array("A", "A1", "S1", "D1")

With sht

    'Loop through each item in Array lists
    For x = LBound(fndList) To UBound(fndList)
        'Loop through each worksheet in ActiveWorkbook
        'For Each sht In ActiveWorkbook.Worksheets("Exp")
        sht.Cells.Replace What:=fndList(x), Replacement:=rplcList(x), _
          lookat:=xlPart, SearchOrder:=xlByRows, MatchCase:=False, _
          SearchFormat:=False, ReplaceFormat:=False
        'Next sht
    Next x
  
End With

I want to only find and replace the array value from first Row A1 till end of 1 row.

Answer 1

Please, try the next way. It will try matching the first array elements on the first row headers and replace the found one with the corresponding string from the second:

Sub ReplaceHeaders()
  Dim shT As Worksheet, lastCol As Long, fndList, rplcList, rngHd As Range, mtch, i As Long
  
  Set shT = ActiveWorkbook.Worksheets("Final Exclusion")
  lastCol = shT.cells(1, shT.Columns.count).End(xlToLeft).Column
  
  fndList = Array("Enter one or more MSOs or ESOs to be excluded.  Separate multiple values using a semicolon.", _
                "Select the datasets from which you wish to exclude these MSOs:", _
                "Select the reason code for the exclusion:", _
                "Submitter's CWSID")

 rplcList = Array("MSO", "SOCS", "Reason's", "Submitter")
 Set rngHd = shT.Range(shT.cells(1, 1), shT.cells(1, lastCol))
 For i = 0 To UBound(fndList)
    mtch = Application.match(fndList(i), rngHd, 0)
    If Not IsError(mtch) Then
        rngHd(1, mtch).Value = rplcList(i)
    End If
 Next i
End Sub