That would be the <a href=”http://spreadsheets.about.com/od/exceltools/ss/81027freezepane.htm”>Freeze Panes feature</a>
•Open a spreadsheet file.
To freeze the top horizontal pane, select the row below where you want the split to appear.
To freeze the left vertical pane, select the column to the right of where you want the split to appear.
To freeze both the upper and left panes, click the cell below and to the right of where you want the split to appear.
Open the Window menu and select Freeze Panes. When you scroll through the worksheet, the area you selected remains on the screen