If you fill this equation to cells below C1, you will get the following: For example, if you create the following equation in row 1 column C. To make cell A1 an absolute reference in a series of equations, enter $A$1. The following is for those unfamiliar with spreadsheets in general. Read on for a longer explanation of fixed cell references and spreadsheets, if you'd like a bit more info on how they work. So if you want a fixed cell reference in your Pages (or Keynote) formula, just enter it as, for example, $B$7, or $B7 to just keep the column fixed.
The feature is the absolute cell reference found in most spreadsheets by using the $ before the column and row address. While there is a lot of room for improvement and enhancement in the tables section of Pages, which I believe is coming soon, I did stumble upon this one which is, to my understanding, not documented.
