Open the VBA window by pressing Alt-F11.
Double click on 'ThisWorkbook' under Microsoft Excel Objects.
Change the drop-down in the window to the right that displays '(General)' to Workbook.
Change the drop-down to the right of that to 'BeforeClose'.
After this:
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Type:
Worksheets("SheetName").Range("A1:A10").Delete Shift:=xlShiftToLeft