Usually when you copy a formula using Fill down or Fill right Fireworkz updates the cell references within the formula as it moves down the column or across the row. If you do not want this to happen, but want to refer to a particular cell explicitly, and always to refer to that cell, in copies of a formula, you must use an absolute reference. You may also make half of the reference absolute, so that different cells within the same column or row are always referenced.
Absolute references are expressed by prefixing the row and column address with dollar signs.
For example:
$A$1
Always refers to the same cell, A1
$A1
Always refers to column A
but the row number will be updated when the formula is copied
A$1
Always refers to row A
but the column is updated when the formula is copied.
You can set up absolute references in the same way as ordinary, relative references, by clicking on cells when you are working on the formula line.
To enter an absolute reference use the right mouse button. This puts both $ signs into the reference; if you only want one, delete the other.
Note that absolute references only make a difference when copying cells from one part of the worksheet to another using Paste, Fill right or Fill down. There is no difference at all between absolute and relative references when inserting or deleting rows and columns in the worksheet. In this case if there is a reference to a cell which moves the reference will always change to reflect the new position.