In Excel, is it possible to protect certain columns but not the whole spreadsheet ?

yes. By default all cells are "protected" although the protection doesn't take effect unless you turn the worksheet protection feature on. To unprotect a cell (or a column) you first have to "unprotect" those cells. To do this right click on a cell and select Format Cells. Go to the "Protection" tab. Uncheck the "locked" option. This will unlock that cell. Now when you protect your workbook, that cell will be unprotected and people can change only that cell.

In your case you want to protect only columns E, F, G and unprotect all others. The easiest way to do this would be to select all cells (press CTRL-A to select all cells). Then right click, select Format cells, go to the Protection tab and turn off the "locked" option on all the cells. All cells would now be unprotected. Now select columns E, F, G and Format cells and "lock" those cells/columns again. And finally protect the workbook as you normally would. Since the only cells that are "locked" are those in E, F, G, the person using the spreadsheet will not be able to change those cells/columns but can change everything else.

I thinkto protect certain columns but not the whole spreadsheet

I think it could not be very feasible to protect certain columns but not the whole spreadsheet

to protect certain columns but not the whole spreadsheet ? yes it can be probable

to protect certain columns but not the whole spreadsheet is not feasible indeed, sorry

this would be easiest if you can add a column to the left of the data in the new column type the formula =RIGHT(B1,2) and copy the formula down the number of used rows now select all of the data and sort using the values in column A hope that helps