Lookup a Value and Return Multiple Results

As you can see the duty number in the sick leave column are in order from the spreadsheet. So if a duty calls in sick from above (earlier start time, as it is sorted by that), the duty on the right hand side is placed above the previously placed duty.
I don't know if I am explaining it right. But if you type "s/l" in the "code" section and above the ones that are already marked, u'll see that the duty you type in will be placed above that in tje right hand side " sick leave section".

Maybe there is a code I can put in to check the "j" column and if it has any value in it then wont change vale if an earlier duty calls in sick.

thank you for your help.