VBA for selecting a range to fill a selection

I have to run reports every week where I show the number of days items are pending some sort of action. I use an autofill action in a macro but the number of rows changes every week. Here is the current section of my macro that I use. I just input a row number that I know will not exceed the number of rows required by my data (12900). What can I replace this with (Selection.AutoFill Destination:=Range("J2:J12900") so it will only fill the number of rows current filled in in either row I or K?

Please Login or Register  to view this content.

I have a date in cell s1 that I subtract from the date in row "I".
I then copy the result of row J and paste it as values.