detect and add the quantities of letters in their groups

Sub X()

    Dim header As Range
    Dim data As Range
    Dim output As Range
    Dim rowIndex As Long
    Dim colIndex As Long
    Dim letterIndex As Long
    Dim letter As String
    Dim tally As Long
    Dim total As Long
    Dim drawData As Range
    Dim drawDataRow As Range
    Dim numberData As Range
    Dim xpos As Variant
    
    Set drawData = Range("A6").CurrentRegion
    
    Set header = Range("I4:AU4") ' assume fixed location
    Set numberData = Range("I5:AU5") ' assume fixed location
    Set data = Range("I6:AU6")
    Set output = Range("AW6")
    
    For Each drawDataRow In drawData.Rows
        
        For colIndex = 1 To drawDataRow.Columns.Count
            xpos = Application.Match(drawDataRow.Cells(1, colIndex), numberData, 0)
            data.Cells(1, xpos) = "X"
        Next
        
        total = 0
        For letterIndex = 1 To 4
            tally = 0
            letter = Chr(64 + letterIndex)
            For colIndex = 1 To data.Columns.Count
                If header.Cells(1, colIndex) = letter Then
                    If Len(data.Cells(1, colIndex)) > 0 Then
                        tally = tally + 1
                    End If
                End If
            Next
            output = tally
            total = total + tally
            Set output = output.Offset(0, 1)
        Next
        output.Offset(0, 1) = total
        Set output = output.Offset(1, -4)   ' move reference down a row
        Set data = data.Offset(1, 0)        ' move reference down a row
    Next
                
End Sub