Cell reference based on active cell

Is there a way to create the chart below based on the active cell I select in a worksheet. Say if I select cell R1 a chart will be created based on that reference so the reference L and M will increase by two letters to T and U reference?

   ActiveChart.ChartType = xlXYScatterLines
    ActiveChart.PlotArea.Select
    ActiveChart.SeriesCollection.NewSeries
    ActiveChart.SeriesCollection(2).XValues = "='" & ActiveSheet.Name & "'!$L$37:$L$49"
    ActiveChart.SeriesCollection(2).Values = "='" & ActiveSheet.Name & "'!$M$37:$M$49"