Hello everybody, I am trying to format an excel file with R, which seems to me a quite hideous task. However, I am using the 'xlsx' package, and I want to change the color of the bottom line without erasing the existing style of a cell. I ran the following code, but it gives me an error and I can't get it to work. wb <- xlsx:::loadWorkbook(file = "Data/test.xlsx") sheet <- xlsx:::getSheets(wb)[[1]] rows <- xlsx:::getRows(sheet, rowIndex=1) cell.1 <- xlsx:::getCells(rows, colIndex=1)[[1]] cs <- xlsx:::getCellStyle(cell.1) + Border(color = "green", position = "BOTTOM") Error in xlsx:::getCellStyle(cell.1) + Border(color = "green", position = "BOTTOM") : non-numeric argument to binary operator What am I doing wrong? Can anyone please help me. Thank you very much! Sincerely, Sören [[alternative HTML version deleted]]