Bookmark the contents of a cell you want to remain static (ie, absolute) using Formula Builder Wizard's new Bookmarking feature. Once the bookmark is created, the bookmark name shows up in the left panel of the Formula Builder Wizard.  Add the bookmark to the formula by double clicking its name.  Add cell addresses to the formula you want Formula Plus Copy and Paste to update by double clicking the cell.  For example, say you want to create a common size income statement.  use the Formula Builder Wizard to bookmark sales data with a name like Sales2008.  Write a formula that divides the cell address for sales by the bookmark name.  The formula may look something like this:

=C3/Sales2008

The results of the above calculation would be 100%

Copy the formula and paste it down for cells next to the other income statement items using Formula Plus Copy and Paste.  Formula Plus Copy and Pate will update the pasted formulas to something like this:

=C4/Sales2008
=C5/Sales2008
=C6/Sales2008
=C7/Sales2008
=C8/Sales2008
=C9/Sales2008

The pasted formula results should reflect their respective income statement items as a percentage of sales.