To do the first bit, try :-
=AT8/$C$8
The $ signs prevent the cell reference changing when it's dragged across or
down.
Have a look in 'Help', enter absolute reference or relative reference and
it's all explained,
Regards,
Alan.
"Redsphynx" wrote in message
...
Hi,

I have a very large spreadsheet, and I need to add another 20 columns in
two
places (20 x 2) but I have formulas I would like to carry across with
them.

In the first group I have a formula like this:

=AT8/C8 AT8=current column and C8=fixed cell and is the same in every
column.

Is there a way to insert a block of columns and they carry the C8 but
change
the AT8 to their own column number??

Second group is a bit more complex....
=IF( X110, X11*F11," ")
X10 refers to column and row but F11 refers to fixed column but
corrisponding row.

I need to add another block of columns that will keep this.

There are about 260 rows in each of these columns, and I would like to do
this as simply as possible.