If you have a graph in Excel that you want to keep people from moving or resizing, you can "lock" the callouts to the graph. This means that when someone tries to move or resize the callouts, they will be unable to do so. The callouts will remain in their original position on the graph.

To lock the callouts to the graph, first select the callouts. Then, go to the "Format" menu and select "Size and Properties." In the "Size and Properties" window, select the "Lock Object" checkbox. Now, when someone tries to move or resize the callouts, they will be unable to do so.