UsedRangeを使用して文字を置換するVBA

Private Sub CommandButton1_Click()
'A1の値を検索し、あればB1の値に置換するマクロ
Dim r As Range
Set r = ThisWorkbook.Sheets("変換リスト").Range("A1")
Dim UsedCell As Range
Dim i As Integer
Dim sss As Variant
Set UsedCell = ThisWorkbook.Sheets("Data").UsedRange
Do Until r.Value = ""
    For i = 1 To UsedCell.Count
    sss = UsedCell(i).Value
        If sss = r.Value Then
            UsedCell(i).Value = Replace(sss, r.Value, r.Offset(, 1).Value)
            UsedCell(i).Interior.ColorIndex = 38
        End If
    Next
    Set r = r.Offset(1)
Loop
MsgBox "complete"
End Sub

Sub Sample()
    Dim RowCnt, ColCnt, StartRow, StartColumn As Integer
    Dim Max_Row, Max_Column, i As Integer
    Dim UsedCell As Range
    Dim UsedArea As String
    
    Set UsedCell = ActiveSheet.UsedRange
    
    UsedArea = UsedCell.Address
    
    StartRow = UsedCell.Cells(1).Row
    StartColumn = UsedCell.Cells(1).Column
    
    Max_Row = UsedCell.Cells(UsedCell.Count).Row
    Max_Column = UsedCell.Cells(UsedCell.Count).Column
End Sub