There are 2 ways, each of which invoke the same feature a bit differently.
1- Go to Window> Split, which will apply both a vertical & a horizontal
split based on the currently selected cell. Once they're turned on the split
lines can be dragged to effect the split as preferred, or
2- There are 'jellybeans' at the top of the vertical scroll bar & right end
of the horizontal scroll bar. Drag or double-click either of them to apply
the split then further adjust as required.
Depending on your actual need, it may be preferable to use the Window>
Freeze Panes feature instead. More info is available in Excel Help.
BTW: Split & Freeze Panes cannot be used at the same time on the same sheet,
& Freeze Panes cannot be used in Page Layout View.
HTH |:>)
Bob Jones
[MVP] Office:Mac