Change Border in Excel left, right, bottom and top

OK I found a solution to do it, here is my code:

xlWorkSheet5.Cells[7,1].Borders[Excel.XlBordersIndex.xlEdgeLeft].Weight = 1d;
xlWorkSheet5.Cells[7, 1].Borders[Excel.XlBordersIndex.xlEdgeRight].Weight = 1d;
xlWorkSheet5.Cells[7,1].Borders[Excel.XlBordersIndex.xlEdgeTop].Weight = 1d;
xlWorkSheet5.Cells[7,1].Borders[Excel.XlBordersIndex.xlEdgeBottom].Weight = 1d;

If you want to use the Borders[index] property then use something along the lines of:

rng.Borders[XlBordersIndex.xlEdgeLeft].LineStyle = XlLineStyle.xlContinuous;
rng.Borders[XlBordersIndex.xlEdgeLeft].ColorIndex = <COLOR THAT YOU WANT>

rng.Borders[XlBordersIndex.xlEdgeTop]...
rng.Borders[XlBordersIndex.xlEdgeBottom]...
rng.Borders[XlBordersIndex.xlEdgeRight]...