Editing info in a table

Hi, I have a table on sheet 2 consisting of 120 rows and 8 columns, on sheet 1 I have a combo box and have used INDEX to display the values for each row that I select. What I want to be able to do is edit the INDEX data on sheet 1 and then have a button that will replace the old value in the table on sheet 2 with the new value. Any help will be greatly appreciated.