Оптимизация кода

Sub InsertDB()
' В редакторе VBA подключаем последнюю версию библиотеки: Microsoft ActiveX Data Objects Library
    
    Dim cn As ADODB.Connection
    Dim cmd As ADODB.Command
    
    Set cn = Nothing
    Set cn = New ADODB.Connection
    Set cmd = New ADODB.Command
        
    R = ThisWorkbook.Sheets(1).UsedRange.Rows.Count
    C = ThisWorkbook.Sheets(1).UsedRange.Columns.Count
    tmp = ThisWorkbook.Sheets(1).Range(Cells(1, 1), Cells(R, C)).Value
    
    cn.ConnectionString = "Driver={Microsoft Access Driver (*.mdb, *.accdb)}; Dbq=G:\Database777.accdb;Uid=Admin;Pwd=;"
    cn.Open
    
    For i = 1 To R
    Sql = "INSERT INTO T1(AAA, BBB) VALUES("
        
        For j = 1 To C
            If j < C Then
                Sql = Sql & tmp(i, j) & ","
            Else
                Sql = Sql & tmp(i, j) & ")"
            End If
        Next j
        cmd.ActiveConnection = cn
        cmd.CommandText = Sql
        cmd.Execute Sql
    Next i
    
    cn.Close
    Set cn = Nothing
 
End Sub

"F22, F23, F24, F25, F26, F27 FROM [Лист1$] AS x IN '" & ThisWorkbook.Path & "\tmp.xlsx' [Excel 16.0; HDR = no;];"

IN '" & ThisWorkbook.Path & "\tmp.xlsx'

cn.Provider = "Microsoft.ACE.OLEDB.16.0"