How to turn off scroll lock on MacBook Pro

How does one turn off scroll lock on a MacBook Pro? Yes, there is no scroll lock key on said machine. However, in Excel, I have somehow managed to activate scroll lock (confirmed by the green button next to "SCRL" at the bottom of the program window). I have tried every apple and microscoft help menu and google result I can find in the last hour and nothing tells me how to turn this off. I see some vague references to F14 and F15, but cannot get any combination of keystrokes to do anything like this. Shift/fn/ctrl/cmd plus F2 and F3 just turns brightness up/down or does undo/redo. This truly bizarre. Help!

MBP 15 Mac OS X (10.4.9)