How to Change a Reference to an Absolute in Excel 2007

1. Place a dollar sign in front of the column delimiter if you want to fix it, and in front of the row delimiter if you want to fix it.For example, you can change =VLOOKUP(A1,K1:P20,4) to =VLOOKUP(A1, $K$1:$P$20, 4) so that the reference to the table's location in K1:P20 won't change if you copy and paste or autofill this formula into empty cells elsewhere.
2. Mix the dollar sign use in order to fill a table. For example, if column headings are in B1 through Y1 and row headings are in A2 through A80, and the cells of the table depend on the values in the headings, then you can enter one cell the right way using mixed absolute references and drag to fill the entire table without the cells incorrectly referencing headings below row 1 or right of column A. For example, enter in B2 the formula =B$1$A2. You'll be able to drag this to fill the entire table because the formulas will always be pointing to the heading row (row 1) and heading column (column A).
3. Use shortcut keys to toggle through the dollar-sign permutations. Specifically, highlight the cell reference that you want to change in the formula bar (the long thin field at the top of the screen). Press the F4 function key to toggle through the different possible placements of $. (This feature doesn't work in some versions of Excel, such as Excel 2004, though it works in 2007.)